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alissre
08-24-2006, 06:02 PM
Hello I am an IL2 Sturmovik beginner, and I have a 2 little questions :

1) FW190 gunsight is located right of center. Does it mean that the direction of flight path is differnet than the direction of fire path ?
If this is the case than how can I catch the target by aiming at the target, because aiming at the target takes me to the right side of the target ?
2) why the designers of FW190 did it ?

many thanks for your help

berg417448
08-24-2006, 06:17 PM
Press Shift + F1 to center your gunsight.

The real gunsight was probably offset to the right in the real plane because most people are right eye dominant.

tigertalon
08-24-2006, 06:22 PM
Hello and wellcome to the community.

Your flightpath is still alignet with gunsight, it's just that gunsight is not at the centre of the plane. Aiming/sighting line is still aligned with longitudional axis of plane and when flying straight ahead with considerable speed, you are generaly flying towards the point in your crosshair.

German planes had gunsight, like berg explained, offset to the right so the pilot didn't need to move head to the left to look through it with the right eye (as he had to do on allied planes). Also most japanese fighters had gunsight offset to the right.

Brain32
08-24-2006, 06:52 PM
Press Shift + F1 to center your gunsight.
Yes and after you do that you will have another question, but I have an answer now: NO it wasn't like that and NO it will not be corrected. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Charos
08-24-2006, 08:49 PM
Originally posted by Brain32:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Press Shift + F1 to center your gunsight.
Yes and after you do that you will have another question, but I have an answer now: NO it wasn't like that and NO it will not be corrected. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif </div></BLOCKQUOTE>

Actually there will be several other questions raised as well and like Brain said the answer to all of them is the same "NO it wasn't like that and NO it will not be corrected." http://forums.ubi.com/images/smilies/sadeyes.gif

alissre
08-24-2006, 09:09 PM
Thank you people, but I steel have some reservations

I changed the setting of the control keys, but I guess its the toggle gunsight key. I know I can see the gunsight completely if I toggle it.
The problem is different:

The german designers logic is now clear to me, but not the game logic. In real life our 2 eyes converge at some point on the distance and their disparity is integrated in the brain to give us a depth perception. So the pilot right-eye looks at the target on the flight path (through the gunsight), just like the left eye is doing. But this is not the case in the game.

JamesBlonde888
08-25-2006, 12:10 AM
Do you call that thing on Japanese planes a gun sight. If I was flying an Oscar then the first thing I would do is havethe silly thing removed and carve some crosshairs on the windscreen. I hate that thing.

KG26_Alpha
08-25-2006, 09:58 AM
LOL The smartie tube sight.

Dont forget the radioactive spider web sight too.hehehe

Chuck_Older
08-25-2006, 10:00 AM
Originally posted by Brain32:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Press Shift + F1 to center your gunsight.
Yes and after you do that you will have another question, but I have an answer now: NO it wasn't like that and NO it will not be corrected. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif </div></BLOCKQUOTE>

Not quite true. The answer is YES it was actually something like that but refraction isn't modelled so it won't be corrected. This has been proven time and again http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

KG26_Alpha
08-25-2006, 10:05 AM
Originally posted by Chuck_Older:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Brain32:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Press Shift + F1 to center your gunsight.
Yes and after you do that you will have another question, but I have an answer now: NO it wasn't like that and NO it will not be corrected. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif </div></BLOCKQUOTE>

Not quite true. The answer is YES it was actually something like that but refraction isn't modelled so it won't be corrected. This has been proven time and again http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif </div></BLOCKQUOTE>

You is "very" wrong be sure.

DuxCorvan
08-25-2006, 05:00 PM
Many of us think Fw 190 flight attitude was a bit more nose-down, and pilot was sitting in a different attitude and had a better view forward. But this has been discussed till boredom, and developers are stubbornly convinced about the correctess of their decision, so no, we'll have to live with it as it is, and I'm afraid a future SoW Fw 190 will be this very same way.

Just accept it and have fun.

Manu-6S
08-25-2006, 05:05 PM
Originally posted by Chuck_Older:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Brain32:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Press Shift + F1 to center your gunsight.
Yes and after you do that you will have another question, but I have an answer now: NO it wasn't like that and NO it will not be corrected. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif </div></BLOCKQUOTE>

Not quite true. The answer is YES it was actually something like that but refraction isn't modelled so it won't be corrected. This has been proven time and again http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif </div></BLOCKQUOTE>

It's the POV position, not the refraction. Simply the camera is too low.

http://img105.imageshack.us/img105/5977/untitled19by.jpg

Pilots real position was the left.

Same thing with Zeroes.

I did an animated gif where you can see better the problem than with the image above.

I think the forum's crash has deleted the thread because I can find it anymore.

Charos
08-25-2006, 06:17 PM
Originally posted by DuxCorvan:
and I'm afraid a future SoW Fw 190 will be this very same way.
Just accept it and have fun.

Over my dead and lifeless body. http://forums.ubi.com/images/smilies/winky.gif

Here is the Montage of which Manu-6S produced - very nice work.

http://img136.imageshack.us/img136/5149/pilot1xk.gif


When one models a FW190 - one must first Be Shore - 100%

WWMaxGunz
08-25-2006, 11:20 PM
The actual FW docs produced by Oleg say 3 or 3.3 degrees, IIRC.
You can measure what we get by the ring being 10 meters wide at 200 meters distance and work it
back from there unless simple trig is beyond you, then get an adult to help.

The inside cockpit is made from blueprints. The freaking Revi is the size it should be and
where it should be. The Revi projects a light pattern along a line the pilot must align his
eye (and only one eye, you close the other to sight a gun else you get parallax -- go take a
gun course if you have doubts) to see at center of the Revi.

So the head position is not off, spend some time doing the geometry on a scale drawing to
maybe figure out that if you raise your eye and look through the center of the glass then
you will get an even worse view over the nose.

Nice pic with the lines but it is NOT of a pilot sighting through the effing Revi, is it?
No, it isn't so zero out of 10 right there.

The problem is as has been shown in detail that over 2 inches thick armor glass tilted at
29 degrees will refract light upwards a good ways. Actually there are several refractions
since there are several layers of glass and plexiglass with refractive indexes of their own
that makes up armor glass but WTH, the effect is to lower the light that comes through the
front. The same refraction also IRL makes the bars look thinner and also warps the view
all the way across and top to bottom measureably and calculably through the THICK GLASS.

The game engine does not model refraction. It can't given our hardware and still run at
playable framerates. We not only get the bar below and thicker to the sides (but less
extra than at the bottom due to less angle) but we also don't get the warpage of the real
view out front either. In fact, we get no refractive effects of any glass or plexi in any
of the planes and btw anyone want to check if the glass used is chromatic or achromatic?
If you don't know, only achromatic glass warps all colors of light the same and no, armor
glass has not that property.

Some of you guys should get an education in what you want to crab out before going off with
your half-invented 'facts'. What you swear is right is no more than fantasy.

Charos
08-26-2006, 02:21 AM
Originally posted by WWMaxGunz:
The actual FW docs produced by Oleg say 3 or 3.3 degrees, IIRC.
You can measure what we get by the ring being 10 meters wide at 200 meters distance and work it
back from there unless simple trig is beyond you, then get an adult to help.


High Max would you have a link to these Oleg produced Documents? or are they in the NDA vault?

Shouldnt I be working back from the 10 Meters ring at 100 Meters distance? Im very new to Mathematical conceps, if your old enough Max perhaps you could help me, I need an Adult.


Originally posted by WWMaxGunz:
The inside cockpit is made from blueprints. The freaking Revi is the size it should be and
where it should be. The Revi projects a light pattern along a line the pilot must align his
eye (and only one eye, you close the other to sight a gun else you get parallax -- go take a
gun course if you have doubts) to see at center of the Revi.


The pilot is not on the Blueprints unfortunately.
And as you rightly point out Max the pilot in the Montage is not in Gunsight view.
To obtain Gunsight view you would have to lean forward not in the seating position as our IL2 avitar is in.
So your saying that in IL2 when we all switch to another view other than gunsight view we will have a view comparable with our montage fellow?

I will wait till you get back from IL2 to let me know how you get on with your non gunsight view.


Originally posted by WWMaxGunz:
So the head position is not off, spend some time doing the geometry on a scale drawing to
maybe figure out that if you raise your eye and look through the center of the glass then
you will get an even worse view over the nose.


So If the pilot was to lift his head higher than sighting view and "look through the center of the glass"
he would "get an even worse view over the nose".
Okey Dokey Max sounds right.



Originally posted by WWMaxGunz:
Nice pic with the lines but it is NOT of a pilot sighting through the effing Revi, is it?
No, it isn't so zero out of 10 right there.


Yes thats very true as I mentioned above to do so requires him to lean forward, a
view at the same level that IL2 utilses pushed forward would reveal a different forward view.

The closer the Pilots eye is at a given hight to the infamous cockpit bar the view angle
downwards will become greater, this is the same as your view for example 100 Meters from a sheer cliff
as compared to standing on the edge, your height has not changed relative to the ground yet
your view into the valley below is now greater.


Originally posted by WWMaxGunz:
The problem is as has been shown in detail that over 2 inches thick armor glass tilted at
29 degrees will refract light upwards a good ways. Actually there are several refractions
since there are several layers of glass and plexiglass with refractive indexes of their own
that makes up armor glass but WTH, the effect is to lower the light that comes through the
front. The same refraction also IRL makes the bars look thinner and also warps the view
all the way across and top to bottom measureably and calculably through the THICK GLASS.

The game engine does not model refraction. It can't given our hardware and still run at
playable framerates. We not only get the bar below and thicker to the sides (but less
extra than at the bottom due to less angle) but we also don't get the warpage of the real
view out front either.

The game engine does not model refraction yet it is willing to model the adverse affects of
not having refraction. An affect that criples the forward view of 50% of all Luftwaffe fighter aircraft
in the game.


Originally posted by WWMaxGunz:
In fact, we get no refractive effects of any glass or plexi in any
of the planes and btw anyone want to check if the glass used is chromatic or achromatic?
If you don't know, only achromatic glass warps all colors of light the same and no, armor
glass has not that property.


The Chromatic properties of sheet glass in this context is not of concern, in an optical system with
a point light source and ground lenses then its an issue.


Originally posted by WWMaxGunz:
Some of you guys should get an education in what you want to crab out before going off with
your half-invented 'facts'. What you swear is right is no more than fantasy.

A high education is a useful tool to have Max, if you have one you will also know that the more you
learn the more you realise you dont know. The law of diminishing returns.

Chuck_Older
08-26-2006, 09:10 AM
Originally posted by KG26_Alpha:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Chuck_Older:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Brain32:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Press Shift + F1 to center your gunsight.
Yes and after you do that you will have another question, but I have an answer now: NO it wasn't like that and NO it will not be corrected. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif </div></BLOCKQUOTE>

Not quite true. The answer is YES it was actually something like that but refraction isn't modelled so it won't be corrected. This has been proven time and again http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif </div></BLOCKQUOTE>

You is "very" wrong be sure. </div></BLOCKQUOTE>

Nawp. No refraction. It doesn't matter that the gunsight is too small and that the 'bar' is too tall. The problem is no refraction modelling. Pourshot and others as well have proved this quite effectively

WWMaxGunz
08-26-2006, 12:53 PM
Originally posted by Charos:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
The actual FW docs produced by Oleg say 3 or 3.3 degrees, IIRC.
You can measure what we get by the ring being 10 meters wide at 200 meters distance and work it
back from there unless simple trig is beyond you, then get an adult to help.


High Max would you have a link to these Oleg produced Documents? or are they in the NDA vault? </div></BLOCKQUOTE>

UBI site crashed in 2003 and lost all posts with no archives.


Shouldnt I be working back from the 10 Meters ring at 100 Meters distance? Im very new to Mathematical conceps, if your old enough Max perhaps you could help me, I need an Adult.

Get behind a fighter with 10m wingspan and icons on and when it fills the ring, check range.
Round to closest 100m as it is 100m or 200m.
Divide 5m by range and that is sine of angle from center to edge of ring.
Trig table at www.themathpage.com/aTrig/trigonometric-table.htm (http://www.themathpage.com/aTrig/trigonometric-table.htm).
Left column is angle when next column number is sine.... looks like 100m may be right, hey?
The ring would be just under 3 degrees and just over the nose but we get like 2.38 degrees
that I am sure you can check.


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
The inside cockpit is made from blueprints. The freaking Revi is the size it should be and
where it should be. The Revi projects a light pattern along a line the pilot must align his
eye (and only one eye, you close the other to sight a gun else you get parallax -- go take a
gun course if you have doubts) to see at center of the Revi.


The pilot is not on the Blueprints unfortunately.
And as you rightly point out Max the pilot in the Montage is not in Gunsight view.
To obtain Gunsight view you would have to lean forward not in the seating position as our IL2 avitar is in. </div></BLOCKQUOTE>

It matters not to have the pilot in the blueprints. The Revi glass throws directed light that
forms the pipper, crosshairs and ring and can be viewed only from limited angles of which only
one will have the ring centered in the glass. You can still see to shoot from off angle but
only slightly off angle, not with head raised high over the coaming.

Think about it. You ever shoot a rifle properly? You must place your eye in line with TWO
sights in order to use them. Revi is an improved form of this.


So your saying that in IL2 when we all switch to another view other than gunsight view we will have a view comparable with our montage fellow?

I will wait till you get back from IL2 to let me know how you get on with your non gunsight view.

I did not place the POV's of the sim but yes the non-gunsight view is slightly higher and
centerline of the plane. You understand that cockpit 3D has no textures on the backs and
sides of objects as seen from the cockpit view positions? Nothing that cannot be seen from
those two. So perhaps the POV possibilities are limited by need for gunsight POV and the
3D makeup of the different planes? Just a thought, ya know?


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
So the head position is not off, spend some time doing the geometry on a scale drawing to
maybe figure out that if you raise your eye and look through the center of the glass then
you will get an even worse view over the nose.


So If the pilot was to lift his head higher than sighting view and "look through the center of the glass"
he would "get an even worse view over the nose".
Okey Dokey Max sounds right. </div></BLOCKQUOTE>

Too effing right. Look at the bottom edge of your monitor and see how much pedestal below
you can see. Now raise your head and see how much less pedestal below the monitor edge you
can see. And before you get too confused, consider the monitor edge to be the CENTER of
the gunsight and how much pedestal is how much below the pipper you will see.

BTW, that is something a 5 year old can be shown so please screw it up!


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
Nice pic with the lines but it is NOT of a pilot sighting through the effing Revi, is it?
No, it isn't so zero out of 10 right there.


Yes thats very true as I mentioned above to do so requires him to lean forward, a
view at the same level that IL2 utilses pushed forward would reveal a different forward view.

The closer the Pilots eye is at a given hight to the infamous cockpit bar the view angle
downwards will become greater, this is the same as your view for example 100 Meters from a sheer cliff
as compared to standing on the edge, your height has not changed relative to the ground yet
your view into the valley below is now greater. </div></BLOCKQUOTE>

POV does never get closer to the Revi and even if it did the projected light ring does get
smaller. If it did not then the use of the ring to judge range to target would be useless.
You are new to all this I suppose and not disposed to thinking when your agenda gets in the
way?


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
The problem is as has been shown in detail that over 2 inches thick armor glass tilted at
29 degrees will refract light upwards a good ways. Actually there are several refractions
since there are several layers of glass and plexiglass with refractive indexes of their own
that makes up armor glass but WTH, the effect is to lower the light that comes through the
front. The same refraction also IRL makes the bars look thinner and also warps the view
all the way across and top to bottom measureably and calculably through the THICK GLASS.

The game engine does not model refraction. It can't given our hardware and still run at
playable framerates. We not only get the bar below and thicker to the sides (but less
extra than at the bottom due to less angle) but we also don't get the warpage of the real
view out front either.

The game engine does not model refraction yet it is willing to model the adverse affects of
not having refraction. An affect that criples the forward view of 50% of all Luftwaffe fighter aircraft
in the game. </div></BLOCKQUOTE>

If you ever work out the angles you will see that the loss is less than 50%. But for purpose
of whining there is always exaggeration.

Yeah, we take a loss. Yes, WE. My squad has long flew LW and I did fly some VEF as LW.
I also much like the FW's and wish things were different but I understand it is not and the
whys that have been given and not being a whiney beotch have accepted it.


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
In fact, we get no refractive effects of any glass or plexi in any
of the planes and btw anyone want to check if the glass used is chromatic or achromatic?
If you don't know, only achromatic glass warps all colors of light the same and no, armor
glass has not that property.


The Chromatic properties of sheet glass in this context is not of concern, in an optical system with
a point light source and ground lenses then its an issue. </div></BLOCKQUOTE>

You're kidding right? I am talking about image warping and spread of light. Positions outside
the glass will be viewed untrue and blurred slightly at angles through very thick glass. The
steep angle of the armorglass and closeness to the pilot makes that certain but we do not have
those negative effects by the same way that we do have the bar cutting some angle below the
pipper off.


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
Some of you guys should get an education in what you want to crab out before going off with
your half-invented 'facts'. What you swear is right is no more than fantasy.

A high education is a useful tool to have Max, if you have one you will also know that the more you
learn the more you realise you dont know. The law of diminishing returns. </div></BLOCKQUOTE>

But you still get the returns. Nothing here is beyond HS level but I have known Art and
Business degree holders with technical understanding less than smart 12 year olds. Oh He!!
I have known Arts majors with less practical sense than Cub Scouts!

When technical people get to something they are not sure of, they stop planning and building
to either learn more or bring in consultants. That is how come we have things like cars,
planes and PC's.

But plain users --- what they don't know never stops them from complaining as if they do.

Manu-6S
08-26-2006, 04:20 PM
I did another montage about the gunsight:

It's an image of our FW190 gunsight with added a filtered part of the gunsight in the Russian video.

I had some problems since the camera of the video was little shifted to left and above all the POV of IL2 is very stretched.

So the trasparent image should be smaller (and therefore the Revi should be bigger).

http://img243.imageshack.us/img243/9896/ttil2ha7.gif

BBB_Hyperion
08-26-2006, 06:01 PM
Originally posted by WWMaxGunz:

You're kidding right? I am talking about image warping and spread of light. Positions outside
the glass will be viewed untrue and blurred slightly at angles through very thick glass. The
steep angle of the armorglass and closeness to the pilot makes that certain but we do not have
those negative effects by the same way that we do have the bar cutting some angle below thepipper off.



On very short range picture is blurred far distance has no noticeable deforming effects. At least from the pilots point of view . Short range here approx. <1 m rest is clear or appears clearer. If that was meant http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Charos
08-27-2006, 04:55 AM
Originally posted by WWMaxGunz:
UBI site crashed in 2003 and lost all posts with no archives.


So do you have a copy of this Document? Seems rather important I should like to aquire a copy.


Originally posted by WWMaxGunz:
Get behind a fighter with 10m wingspan and icons on and when it fills the ring, check range.
Round to closest 100m as it is 100m or 200m.
Divide 5m by range and that is sine of angle from center to edge of ring.
Trig table at www.themathpage.com/aTrig/trigonometric-table.htm (http://www.themathpage.com/aTrig/trigonometric-table.htm).
Left column is angle when next column number is sine.... looks like 100m may be right, hey?
The ring would be just under 3 degrees and just over the nose but we get like 2.38 degrees
that I am sure you can check.


Oh im glad its now 10M at 100M before when you mentioned it was 10M at 200M I thought I must have been in error.
Your 2.38 Degrees sounds about spot on to me, actually we should really use Tan trig function here.

I will now Quote Mr Eric Brown:

"Sighting View
"The sighting view, when sitting comfortably in the normal position, is about half a ring better than that from the spitfire. The view downwards from the centre of the sight graticule to the edge of the reflector plate holder, is about 5 degrees. This view is not obtained by elevateing the gun (and consequently the sight) relative to the line of flight, but is entirely due to the attitude of the aircraft in flight, which is nose down." (He means nose down relative to the pilots view NOT from an external view.

Ok here he says two things.

#1 The sighting view, when sitting comfortably in the normal position, is about half a ring better than that from the spitfire.

#2 The view downwards from the centre of the sight graticule to the edge of the reflector plate holder, is about 5 degrees.


From the above #1 is from the normal seating position and #2 pertains to the sighting view.

In #1 its a half a ring BETTER than the Spitfire - If the Spitfires view is Half a Ring (its probably more) - then we have more than 6.2 Degree's total.

In #2 we have 5 Degrees from the Sighting graticule to the reflector plate. IE: View angle over cowling.


If you take note of the FB centered views I posted you will note they are lower, there is only 1.5 Graticule pips
from Centre sighting line and the Bar this stranslates to approx 1.43 Degrees

In other words we are approx out by a factor of (6.2/1.43=4.3) with our forward decliation view angle in centered view.

Yes thats right a factor of 430%




Originally posted by WWMaxGunz:
It matters not to have the pilot in the blueprints. The Revi glass throws directed light that
forms the pipper, crosshairs and ring and can be viewed only from limited angles of which only
one will have the ring centered in the glass. You can still see to shoot from off angle but
only slightly off angle, not with head raised high over the coaming.

Think about it. You ever shoot a rifle properly? You must place your eye in line with TWO
sights in order to use them. Revi is an improved form of this.



Yes I agree with you for the Gunsight view but not the normal seating view which is slightly higher and rearward than Sighting view.

Yes I have shot a rifle both Iron sights and Scoped.




Originally posted by WWMaxGunz:
I did not place the POV's of the sim but yes the non-gunsight view is slightly higher and
centerline of the plane. You understand that cockpit 3D has no textures on the backs and
sides of objects as seen from the cockpit view positions? Nothing that cannot be seen from
those two. So perhaps the POV possibilities are limited by need for gunsight POV and the
3D makeup of the different planes? Just a thought, ya know?



Your incorrect Max, the Centered Views (Non Gunsight views) are infact LOWER.

Yes I understand the Limitations on the Cockpit models, But this issue is addressed in
the ME262 cockpit for example - Where non sight views are higher. So it can be done.

I will wait till you check that out and come back.

Before you go though here are the 4 possible FW190 cockpit views in game.

You will notice that both Centered views are 1 Graticule mark lower than the Sighted views.

This has been modeled because the pilot relaxes backward in non Sighting views, I dont have an issue with that at all
its spot on.

What I do have an Issue with is that the associated perspective of the head being raised while ralxed back is NOT Modeled.


http://members.optusnet.com.au/~trentelliott/FW190/190A4_Gunsight.gif

http://members.optusnet.com.au/~trentelliott/FW190/190A4_GunsightCentre.gif

http://members.optusnet.com.au/~trentelliott/FW190/190A4_GunsightNormal.gif

http://members.optusnet.com.au/~trentelliott/FW190/190A4_NormalCentre.gif



Originally posted by WWMaxGunz:
Too effing right. Look at the bottom edge of your monitor and see how much pedestal below
you can see. Now raise your head and see how much less pedestal below the monitor edge you
can see. And before you get too confused, consider the monitor edge to be the CENTER of
the gunsight and how much pedestal is how much below the pipper you will see.

BTW, that is something a 5 year old can be shown so please screw it up!


Oh I follow you perfectly - thank goodness I thought I had regressed several years.

The example you provided is the inverted situation of the one I provided.

In your case the monitor sits directly over the pedestal, in the FW190 this would be
like seeing less of the rudder peddles as you move your view forward. Simply because they are
obstructed by the intrument panel.

In my example there is nothing obstructing the view of the valley below but the Cliff top edge, this would
be the infamous bar in our FW190 example.

The difference is that in my example there is nothing over the valley but sky in your example the pedastal
is obstructed when viewed from above.

They are examples of two different situations.


You can see this in effect in the pictures I provided above.



Originally posted by WWMaxGunz:
POV does never get closer to the Revi and even if it did the projected light ring does get
smaller. If it did not then the use of the ring to judge range to target would be useless.
You are new to all this I suppose and not disposed to thinking when your agenda gets in the
way?


This sounds like something from Raaid.
Lets consider our Target ring of 10M at 100M has a Spitfire in it at 100M (lets not be pedantic, I know
it wont be an exact fit).
If you move your eye 10cm away or closer from the sight you have to correct for a 1/1000 deviation.

Instead you will find if the pilots eye is not in the optimum distance from the sight it will instead be out of focus.

You should check out a nice video of the Revi12 made by the lads at JG4.



Originally posted by WWMaxGunz:
If you ever work out the angles you will see that the loss is less than 50%. But for purpose
of whining there is always exaggeration.

Yeah, we take a loss. Yes, WE. My squad has long flew LW and I did fly some VEF as LW.
I also much like the FW's and wish things were different but I understand it is not and the
whys that have been given and not being a whiney beotch have accepted it.


No Max the 50% loss was in context to the FW190 and the BF109 being the only two Single Engine fighter AC of the Luftwaffe, ignoring
all other banned types online IE: ME262 etc etc. Hence this issue affects 50% of every AC flown in the game by Blue.

I always prefer facts and have no agenda to exaggerate anything.

If you are attempting to point out an inaccuracy in this "Simulation" you should not consider yourself a Whiney beotch if you have a
sound case. I could care less what people think of myself, I will happily admit if I am wrong - Im still waiting for proof otherwise on the FW190 issue.



Originally posted by WWMaxGunz:
You're kidding right? I am talking about image warping and spread of light. Positions outside
the glass will be viewed untrue and blurred slightly at angles through very thick glass. The
steep angle of the armorglass and closeness to the pilot makes that certain but we do not have
those negative effects by the same way that we do have the bar cutting some angle below the
pipper off.



No im serious, do you think Luftwaffe pilots wore corrective contact lenses or did Kurt Tank
just say oh well its a fighter aircraft I guess we can live with crappy pilot view.?

BBB_Hyperion has already made comment on this, you will have to work it out on your own.



Originally posted by WWMaxGunz:
But you still get the returns. Nothing here is beyond HS level but I have known Art and
Business degree holders with technical understanding less than smart 12 year olds. Oh He!!
I have known Arts majors with less practical sense than Cub Scouts!

When technical people get to something they are not sure of, they stop planning and building
to either learn more or bring in consultants. That is how come we have things like cars,
planes and PC's.

But plain users --- what they don't know never stops them from complaining as if they do.


Oh yes an education is a wonderful thing, but like the force one must be careful when wielding it.

WWMaxGunz
08-27-2006, 07:41 AM
Originally posted by Charos:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
UBI site crashed in 2003 and lost all posts with no archives.


So do you have a copy of this Document? Seems rather important I should like to aquire a copy. </div></BLOCKQUOTE>

Good luck then.


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
Get behind a fighter with 10m wingspan and icons on and when it fills the ring, check range.
Round to closest 100m as it is 100m or 200m.
Divide 5m by range and that is sine of angle from center to edge of ring.
Trig table at www.themathpage.com/aTrig/trigonometric-table.htm (http://www.themathpage.com/aTrig/trigonometric-table.htm).
Left column is angle when next column number is sine.... looks like 100m may be right, hey?
The ring would be just under 3 degrees and just over the nose but we get like 2.38 degrees
that I am sure you can check.


Oh im glad its now 10M at 100M before when you mentioned it was 10M at 200M I thought I must have been in error.
Your 2.38 Degrees sounds about spot on to me, actually we should really use Tan trig function here.

I will now Quote Mr Eric Brown:

"Sighting View
"The sighting view, when sitting comfortably in the normal position, is about half a ring better than that from the spitfire. The view downwards from the centre of the sight graticule to the edge of the reflector plate holder, is about 5 degrees. This view is not obtained by elevateing the gun (and consequently the sight) relative to the line of flight, but is entirely due to the attitude of the aircraft in flight, which is nose down." (He means nose down relative to the pilots view NOT from an external view.

Ok here he says two things.

#1 The sighting view, when sitting comfortably in the normal position, is about half a ring better than that from the spitfire.

#2 The view downwards from the centre of the sight graticule to the edge of the reflector plate holder, is about 5 degrees.


From the above #1 is from the normal seating position and #2 pertains to the sighting view.

In #1 its a half a ring BETTER than the Spitfire - If the Spitfires view is Half a Ring (its probably more) - then we have more than 6.2 Degree's total.

In #2 we have 5 Degrees from the Sighting graticule to the reflector plate. IE: View angle over cowling. </div></BLOCKQUOTE>

I don't agree about your interpretation of Eric Brown's words. I read it as he is able to see
the sighting view from comfortable seating normal to sighting. The Revi is pretty high up on
the dash. To get the head higher and look over the nose better I think takes more of a sit up
to look than sit back to sight but that is my idea based on texts and pictures long time now.

5 degrees would be about half a ring and a bit below the pipper, no?

This puts us back about the points of the debates long ago where it was stated that refraction
that would cause all beyond the glass or at least the lower area of the glass to appear lower
will not be modelled nor corrected for. You either accept or not but there is and has been no
point trying for change.

--------------------------------------------------------------------------------------------

As for the rest there are only two head positions with many FOV angles possible for each.
Head does not get closer to the front of the plane with zoom. Instruments appear larger due
to having more of the screen to be painted on just as zooming with binoculars does not make
me closer to viewed scene.

Yes thick flat glass will warp positions and images slightly. Notice eyeglass inner curve
stays at a constant radius from the eye lens or tries to, that eyeglasses are not flat and
if so would be terrible to see through. FW windshield has some angle from center to edge
back to pilot POV and a calculable warpage that was acceptable but hey we do not get any.

The 29 degree tilt of the glass though is AFAIC a design element of the Revi optics that I
like many did argue should be compensated for and we lost. What is the difference in angle
from pilot position at the bottom of the armorglass compared to the top? More than center
to side. SLIGHT warpage in positions compared to real.
Oleg had taken a position about refractive effects that included all views in all planes
including curved plexi of hoods. In many cases near edges, etc, the warpage would be much
more. If he can't do for all then he does for none. And I don't see that refraction will
be done any time soon so only hope for upcoming SOW FW's is that Oleg changes his stance
and permits work-arounds that I am sure the majority of us will applaud loudly, myself
included.


Time to put up the miserable trueisms like raising pilot eye would help aside. The pilot
only ends up looking DOWN at the Revi and seeing less over the nose THROUGH the Revi. And
sighting is done through the Revi not over it. In the lost posts we also had exactly such
a view directly from Oleg generated at Maddox Games to show how wrong that idea is. I guess
you had to be here or at least remember what was posted.

Funny but when I did fire belt-fed MG in service that I did not look through the sights at all
but stayed head over the barrel and watched where the strikes landed. And I was good at
placing the first burst even to 800 yards with M-60. It is a matter of practice and feel for
where the shots go which IMO is superior anyway but in the sim takes a LOT of gunnery practice.
Get in close and who needs the freaking sights? They aren't so great way inside convergence
except for nose guns.

Asgeir_Strips
08-27-2006, 08:05 AM
interesting discussion, but what about Allied Gunsights? (US and British primarily) i sat in a spitfire with a functional gunsight once, and i didn't have to use the left eye, or the right eye to "aim". I used both eyes.

Manu-6S
08-27-2006, 09:18 AM
Originally posted by WWMaxGunz:
Time to put up the miserable trueisms like raising pilot eye would help aside. The pilot
only ends up looking DOWN at the Revi and seeing less over the nose THROUGH the Revi. And
sighting is done through the Revi not over it. In the lost posts we also had exactly such
a view directly from Oleg generated at Maddox Games to show how wrong that idea is. I guess
you had to be here or at least remember what was posted.

Funny but when I did fire belt-fed MG in service that I did not look through the sights at all
but stayed head over the barrel and watched where the strikes landed. And I was good at
placing the first burst even to 800 yards with M-60. It is a matter of practice and feel for
where the shots go which IMO is superior anyway but in the sim takes a LOT of gunnery practice.
Get in close and who needs the freaking sights? They aren't so great way inside convergence
except for nose guns.

Since I'm stupid can you make a design to demostrate it?

And in your last statement are you saying that gunsight is useless?

Brain32
08-27-2006, 09:30 AM
MaxGunz and others, with all due respect:
Fact #1 - Fw190 has exceptional all around visibility especially frontal, compared with the buuble canopy Mustang, Thunderbolt, Tempest, it was better than Spitfire, Me109 and many others.
Fact #2 - Fw190 has one of the worst, and considering the ballistic characteristics of the weapons it uses, it has THE WORST frontal visibility of all the planes modelled in the game.
Conclusion: The frontal view is WRONG!!!
Not that hard is it?

Manu-6S
08-27-2006, 10:02 AM
Originally posted by Brain32:
MaxGunz and others, with all due respect:
Fact #1 - Fw190 has exceptional all around visibility especially frontal, compared with the buuble canopy Mustang, Thunderbolt, Tempest, it was better than Spitfire, Me109 and many others.
Fact #2 - Fw190 has one of the worst, and considering the ballistic characteristics of the weapons it uses, it has THE WORST frontal visibility of all the planes modelled in the game.
Conclusion: The frontal view is WRONG!!!
Not that hard is it?

Please, don't feed Max... http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

WWMaxGunz
08-27-2006, 11:14 AM
Originally posted by Brain32:
MaxGunz and others, with all due respect:
Fact #1 - Fw190 has exceptional all around visibility especially frontal, compared with the buuble canopy Mustang, Thunderbolt, Tempest, it was better than Spitfire, Me109 and many others.
Fact #2 - Fw190 has one of the worst, and considering the ballistic characteristics of the weapons it uses, it has THE WORST frontal visibility of all the planes modelled in the game.
Conclusion: The frontal view is WRONG!!!
Not that hard is it?

Not hard at all. I posted many times many things to try and present for a change. Many times.
I even showed how to use the sim itself to show the error to close degree as I did in this
thread.

Here is the hard part. Accept that it will not change and that the reasons Oleg has given are
enough. Let go of the personal attachments, nobody will die over this.

Manu-6S
08-27-2006, 11:22 AM
1)

Here there is a issue of our Revi 16B:

http://img125.imageshack.us/img125/4452/revijc0.jpg

And these are the plans:

http://www.albentley-drawings.com/images/Revi16B.jpg

Do you see? The glass have the same box's width.

2)

Here there is a comparison between the real FW190 gunsight (Revi C12/D) and the Revi 16B of IL2's FW190.

http://img129.imageshack.us/img129/1285/confrontoid1.jpg

Look at the boxes: they book the same space and probably the second one is bigger.

3)

Finally here there's our FW with Revi C12/D of the russian video.
http://img182.imageshack.us/img182/729/sovrus8.jpg

I stretched the b/w image to make it similar to our cockpit (the best I could do, sorry)

WWMaxGunz
08-27-2006, 11:38 AM
Originally posted by Manu-6S:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
Time to put up the miserable trueisms like raising pilot eye would help aside. The pilot
only ends up looking DOWN at the Revi and seeing less over the nose THROUGH the Revi. And
sighting is done through the Revi not over it. In the lost posts we also had exactly such
a view directly from Oleg generated at Maddox Games to show how wrong that idea is. I guess
you had to be here or at least remember what was posted.

Funny but when I did fire belt-fed MG in service that I did not look through the sights at all
but stayed head over the barrel and watched where the strikes landed. And I was good at
placing the first burst even to 800 yards with M-60. It is a matter of practice and feel for
where the shots go which IMO is superior anyway but in the sim takes a LOT of gunnery practice.
Get in close and who needs the freaking sights? They aren't so great way inside convergence
except for nose guns.

Since I'm stupid can you make a design to demostrate it? </div></BLOCKQUOTE>

Place a pen on an empty table and with your head low place another object on the table so that
the bottom edge appears to line up with the top edge of the pen.
Now raise your head a bit and place another object so that it appears to line up with the top
edge of the pen.
The second object will be closer to the pen, the view is shorter.

If you can raise your head and still see through the Revi center, the view through the sight
will not even clear the nose of the plane.


And in your last statement are you saying that gunsight is useless?

The last statement is exactly what it is. Where did I use the word useless?
Set convergence for 250m and shoot with wing guns at 100m or less, the shots will not pass or
hit the target where the pipper is but below instead. From very close there is no need to do
other than look over the nose if you know about where the rounds will go. Simple as that.
Read from the aces of WWI and WWII they say the same thing, up close you don't have to aim.

I shoot deflection from long range in and yeah I use the sight and ring to guess at where to
start my aim but hey I work by tracers and hits to make correction as well.

Don't they have rifles where you are? Has nobody ever trusted you with one? I've had my own
and a lot of time spent shooting since I was 12. I know that I can sight a rifle and if I
raise my head that I can no longer sight the rifle, but I can look over it and still shoot.
It depends on how accurate I want to be. Size of human eye at more than 3m I had to use sights,
size of human head to 15m I did not and could do much quicker without using sights.

WWMaxGunz
08-27-2006, 12:22 PM
Originally posted by Manu-6S:
1)

Here there is a issue of our Revi 16B:

http://img125.imageshack.us/img125/4452/revijc0.jpg

And these are the plans:

http://www.albentley-drawings.com/images/Revi16B.jpg

Do you see? The glass have the same box's width.

2)

Here there is a comparison between the real FW190 gunsight (Revi C12/D) and the Revi 16B of IL2's FW190.

http://img129.imageshack.us/img129/1285/confrontoid1.jpg

Look at the boxes: they book the same space and probably the second one is bigger.

3)

Finally here there's our FW with Revi C12/D of the russian video.
http://img182.imageshack.us/img182/729/sovrus8.jpg

I stretched the b/w image to make it similar to our cockpit (the best I could do, sorry)

Revi glass in the photo looks wider than the housing beneath it. How much is due to camera
perspective I cannot say but it looks wider. It is also 16C/D... should be what model FW?

Those _plans_ are a subassembly drawing and the top screenshot ... kinda sucks.

I just ran a QM with 190A-4 and turned the plane till I got some daylight onto the guages
and lower Revi housing.
It is grey and you can see two seperate vertical parts. Wider one is left and lines up
with the glass above but if anything is narrower than the glass. The grey part to the
right looks about as wide as a pen. There is a shadow between as if the two parts have
rounded edges or are round. The part on the right has a brownish thing at the bottom
that looks like a knob. This is what I see when I paused and zoom all the way in and
moused the view onto the Revi glass and lower part. Sorry but my dialup does not include
web page space and anyway you or anyone can see the same thing by doing the same thing.
Hardest part is getting any decent sunlight onto that part of the instruments as it is
all very dark otherwise. Try setting time to 1600 hours and fly SSE... 100-110 degrees?

Manu-6S
08-27-2006, 12:36 PM
Originally posted by WWMaxGunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Manu-6S:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
Time to put up the miserable trueisms like raising pilot eye would help aside. The pilot
only ends up looking DOWN at the Revi and seeing less over the nose THROUGH the Revi. And
sighting is done through the Revi not over it. In the lost posts we also had exactly such
a view directly from Oleg generated at Maddox Games to show how wrong that idea is. I guess
you had to be here or at least remember what was posted.

Funny but when I did fire belt-fed MG in service that I did not look through the sights at all
but stayed head over the barrel and watched where the strikes landed. And I was good at
placing the first burst even to 800 yards with M-60. It is a matter of practice and feel for
where the shots go which IMO is superior anyway but in the sim takes a LOT of gunnery practice.
Get in close and who needs the freaking sights? They aren't so great way inside convergence
except for nose guns.

Since I'm stupid can you make a design to demostrate it? </div></BLOCKQUOTE>

Place a pen on an empty table and with your head low place another object on the table so that
the bottom edge appears to line up with the top edge of the pen.
Now raise your head a bit and place another object so that it appears to line up with the top
edge of the pen.
The second object will be closer to the pen, the view is shorter.

If you can raise your head and still see through the Revi center, the view through the sight
will not even clear the nose of the plane.


And in your last statement are you saying that gunsight is useless?

The last statement is exactly what it is. Where did I use the word useless?
Set convergence for 250m and shoot with wing guns at 100m or less, the shots will not pass or
hit the target where the pipper is but below instead. From very close there is no need to do
other than look over the nose if you know about where the rounds will go. Simple as that.
Read from the aces of WWI and WWII they say the same thing, up close you don't have to aim.

I shoot deflection from long range in and yeah I use the sight and ring to guess at where to
start my aim but hey I work by tracers and hits to make correction as well.

Don't they have rifles where you are? Has nobody ever trusted you with one? I've had my own
and a lot of time spent shooting since I was 12. I know that I can sight a rifle and if I
raise my head that I can no longer sight the rifle, but I can look over it and still shoot.
It depends on how accurate I want to be. Size of human eye at more than 3m I had to use sights,
size of human head to 15m I did not and could do much quicker without using sights. </div></BLOCKQUOTE>

Yes, I understand: it was obvious, but I wanted to be sure http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

I agree, but with a bigger Revi (my post above) the pilot could stay higher and be in the right line with the nose (in Il2 he's a lot lower).

I don't know if you understand me, I'll make another design.

I said useless because it's what I understood in the main of your statement... I shoot without Revi too (above all for deflection shoot), but sometimes you have to aim and since, like Charos proved, we have a gunight POV HIGHER than the normal view...

Manu-6S
08-27-2006, 12:49 PM
Originally posted by WWMaxGunz:
Revi glass in the photo looks wider than the housing beneath it. How much is due to camera
perspective I cannot say but it looks wider. It is also 16C/D... should be what model FW?


As I said before the camera was shifted to the left, but you can realign it easily. Do you see that the leather part of cockpit is not wider than our cockpit? I have to transform the original image to have the same with for the frontal bar. So the Revi should be a little bigger, but I think it's right as I did.

Revi C12/D, I wrote it above...

FW version? I don't remember... A-3 or A-4 IIRC, maybe another poster can help us.


Originally posted by WWMaxGunz:
I just ran a QM with 190A-4 and turned the plane till I got some daylight onto the guages
and lower Revi housing.
It is grey and you can see two seperate vertical parts. Wider one is left and lines up
with the glass above but if anything is narrower than the glass. The grey part to the
right looks about as wide as a pen. There is a shadow between as if the two parts have
rounded edges or are round. The part on the right has a brownish thing at the bottom
that looks like a knob. This is what I see when I paused and zoom all the way in and
moused the view onto the Revi glass and lower part. Sorry but my dialup does not include
web page space and anyway you or anyone can see the same thing by doing the same thing.
Hardest part is getting any decent sunlight onto that part of the instruments as it is
all very dark otherwise. Try setting time to 1600 hours and fly SSE... 100-110 degrees?

I can't play due videocard problem but I always noticed it. I used the image that Charos posted.

btw, how can you say about the point 2?

WWMaxGunz
08-27-2006, 09:32 PM
Point 2?

Besides the camera being POV higher, closer and not pointing straight front of plane it
does appear to show a wider Revi. It also shows a different model Revi.

That one in the pic has hard to judge how much gap to the right of the glass and inside of
strut but may be as the one modelled. Left edge of glass is possibly center or left of
center of the padding, definitely wider, not as one modelled.

Between 12/D and 16B Revi the width should be the same? I note that center of both are
farther right than average distance of right eye from bridge of nose. Perhaps that is
to let the pilot see past the Revi for normal flying? If so then improved model may well
be slimmer to give better non-gunsight view.

Also IRL the struts on the left, right, and above outside elements should appear thinner
to some small degree due to refraction and thickness of the glass. We don't get that.

It has been so long since I made a screenshot and I don't see the key in Controls section,
what is the key to make a screenshot?

Charos
08-27-2006, 10:34 PM
Originally posted by WWMaxGunz:

Good luck then.


Someone must have kept an archive of these documents, If anybody has a copy I would love to have a look. Please drop me a PM. Thankyou.



Originally posted by Charos:
I will now Quote Mr Eric Brown:

"Sighting View
"The sighting view, when sitting comfortably in the normal position, is about half a ring better than that from the spitfire. The view downwards from the centre of the sight graticule to the edge of the reflector plate holder, is about 5 degrees. This view is not obtained by elevateing the gun (and consequently the sight) relative to the line of flight, but is entirely due to the attitude of the aircraft in flight, which is nose down." (He means nose down relative to the pilots view NOT from an external view.




Originally posted by WWMaxGunz:
I don't agree about your interpretation of Eric Brown's words. I read it as he is able to see
the sighting view from comfortable seating normal to sighting. The Revi is pretty high up on
the dash. To get the head higher and look over the nose better I think takes more of a sit up
to look than sit back to sight but that is my idea based on texts and pictures long time now.

5 degrees would be about half a ring and a bit below the pipper, no?

This puts us back about the points of the debates long ago where it was stated that refraction
that would cause all beyond the glass or at least the lower area of the glass to appear lower
will not be modelled nor corrected for. You either accept or not but there is and has been no
point trying for change.


I think your right max it was getting late last night when I posted so yes it appears this whole entire paragraph pertains to the sighting view itself which is logical given the title.

5 degrees is nearly an entire rings worth in angular view. At the moment we have have 2.43 Degrees or thereabouts from pipper to bar which is actually higher than the
€œedge of the reflector plate holder€ in IL2.


If the normal Gun ring provides 5.7 Degrees or better (10M ring at 100 M range) €" If we assume the Germans calibrated for a Spitfire at 100M then it must have a greater angle diameter ring than 6 Degrees 44 Seconds which is the spitfire€s sight ring diameter (Calibrated for 35 Feet at 100 Yards).

What Eric Brown appears to be saying when I look at it again is that €œ The view downwards from the centre of the sight graticule to the edge of the reflector plate holder, is about 5 degrees€.

This can only mean if the Sight is calibrated for approx 17.5M ring at 100M (10 Degree ring at
100M IE: then the bottom of the Ring should be just touching the obstruction of the €œedge of the reflector plate holder€.

A quick Calculation of Glass 50mm thick with a refractive index of 1.5 on an angle of incidence of 29 Degrees provides a refractive angle of 18.86 Degrees and a vertical offset of 16.16mm.

We now need to find out what physical ring size the Revi16B paints on the reflector glass to compare how much 16.16mm relative offset by the armour glass refraction gives us.

Manu your right someone put the Revi16 on a diet
on the upper half - will have to get home to check if this is the case in all AC or just FW190.
If its just the FW190 it raises another question.
http://mezek.valka.cz/texty/letadla/revi16b/revi16b.jpg

Max just use Print screen it will dump a JPG into your default IL2 directory.

WWMaxGunz
08-28-2006, 05:54 AM
I don't think you have to calculate anything since Eric Brown made the observation.

However the IRL observation includes refraction which will not be modelled, etc.
The horse died 4 years ago. These posts parody a dream from Crime and Punishment.

WWMaxGunz
08-28-2006, 06:04 AM
ha! I did make a screenie but since I saw no notice I thought I didn't.
The file I get is TGA, not JPG.
So I put it into graphics package and enhanced the color levels and clearly there are two
pieces below the leather padding.

Manu-6S
08-28-2006, 07:35 AM
Originally posted by WWMaxGunz:
the camera being POV higher, closer and not pointing straight front of plane it
does appear to show a wider Revi. It also shows a different model Revi.


No, the leather padding in the video isn't wider than our, try to look better. And I repeat, I stretched the picture to made it similar to the frontal bars. The only different thing caused by the left shifting is that the glasses are not centered.


Originally posted by WWMaxGunz:
Between 12/D and 16B Revi the width should be the same? I note that center of both are
farther right than average distance of right eye from bridge of nose.


I can't find any plan with measures, but looking at the photos they seem to have the same width (Revi C12/D housing is different, it's not all inside a single box... so it seems the glasses are wider than the housing, but they aren't).

Refraction IS modelled because the bar in front should be 65mm (IIRC) but the refraction mades it thinner... maybe not enought.

Charos
08-28-2006, 04:12 PM
I find the situation rather sad when Mods feel they need to move a thread of this nature from Oleg's Ready Room to the General discussion forum.

But they are content to leave untouched the following.

"Oleg, Plz model the MIG-28"

This topic clearly covers an outstanding issue with the game in question.

There was tongue in cheek comments but nothing outlandish.

No matter I have other means open to me - But I
must say I find it sad the community cant openly discuss valid game issues on Olegs Forum.

Either close ORR or add the MIG28 http://forums.ubi.com/images/smilies/shady.gif to the game, I assume that posts validity must be more relevent.
And no moveing that post to General will not justify previous actions.
__________________________________________________ ___________________________
Purpose of Oleg`s Ready Room:

1) Dialog with the developer:

a) Questions regarding IL-2 series and future flight simulations.
b) Suggestions for current products and future line of products.
c) Personal questions €" but please, be reasonable

2) Bugs and possible inaccuracies reporting:

Bottom line:

Anything that doesn€t meet this criteria will be moved out to general discussion or deleted.

Also, from now on - Tagert, Buzzsaw, Gibbage and Maxgunz are not allowed to participate in the threads started by Kurfurts and in the same time, Kufurst is not allowed to participate in theirs. This is new rule, I just made that up in order to keep this place somewhat sane. Too many interesting threads were locked because of you guys... and you are the ones to blame. I hope we are clear on this one.

V!
Regards,

luftluuver
08-28-2006, 04:17 PM
Charos,

you can get the 190 drawings from
http://www.albentley-drawings.com/

Charos
08-28-2006, 04:24 PM
Originally posted by luftluuver:
Charos,

you can get the 190 drawings from
http://www.albentley-drawings.com/

Thanks Luftluuver. http://forums.ubi.com/images/smilies/25.gif

I know of Mr Bentley's work - his line drawings are simply amazing and very accurate.

Alot of Blue Prints with subassemblies are also available of DVD now, there's lots of good info getting around these days.
Its like being a kid in a candy store.

luftluuver
08-28-2006, 04:37 PM
One can get all sorts of manuals/pilot handbooks for German a/c from, http://www.luftfahrt-archiv-hafner.de/

Tully__
08-29-2006, 07:08 AM
Originally posted by Charos:
...We now need to find out what physical ring size the Revi16B paints on the reflector glass...

Can't be done. The reticle is not projected on the glass, it is projected at infinity (or nearly so) and is reflected by the glass. It subtends a (nearly) constant angle to the viewer regardless of the distance of the viewer from the sight glass so the apparent size of the reticle in relation to the glass will vary depending on viewing distance. When the viewer is close to the glass the reticle will seem small in relation to the glass. As the viewer moves back, the reticle will appear to grow to fill the glass but will remain apparently the same size in relation to an object 100m or more away.

Tully__
08-29-2006, 07:29 AM
Originally posted by Charos:
I find the situation rather sad when Mods feel they need to move a thread of this nature from Oleg's Ready Room to the General discussion forum.

But they are content to leave untouched the following.

"Oleg, Plz model the MIG-28"

This topic clearly covers an outstanding issue with the game in question.
I don't get in ORR much but I do get in there enough to know that as far as the developers are concerned the Fw190 front view is a closed issue. ORR is there to discuss potential changes and bugs the developers may not be aware of. Oleg and his team are very well aware of this issue and all the evidence relating to it and it no longer has a place in ORR as they have clearly and repeatedly stated that they are not going to do anything about it and why. Consequently any thread relating to this issue for a long time and all future threads are being moved to general discussion (unless they slide into oblivion before being spotted by a moderator) to try & help with the clutter in ORR.

WWMaxGunz
08-29-2006, 07:58 AM
Originally posted by Manu-6S:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WWMaxGunz:
the camera being POV higher, closer and not pointing straight front of plane it
does appear to show a wider Revi. It also shows a different model Revi.


No, the leather padding in the video isn't wider than our, try to look better. And I repeat, I stretched the picture to made it similar to the frontal bars. The only different thing caused by the left shifting is that the glasses are not centered.

</div></BLOCKQUOTE>

The stretching to match was a bad thing as the 'cameras' are at two different distances and
heights from the subject plus the 'lens' of the 'IL2 camera' is FOV controlling and not true
for measuring by. However what I went by strictly is ratio of Revi width to padding in each
picture although as I say the photo has angle that makes that imperfect.

WWMaxGunz
08-29-2006, 08:01 AM
Originally posted by Tully__:
When the viewer is close to the glass the reticle will seem small in relation to the glass. As the viewer moves back, the reticle will appear to grow to fill the glass but will remain apparently the same size in relation to an object 100m or more away.

When I posted that I was told the reticle will blur. Thought I had it right.
It's a very good sight though. Beats lining up iron sites, tubes and such.

Tully__
08-29-2006, 08:22 AM
When I posted that I was told the reticle will blur
It may in some reflector sights or for some pilots, it depends on the depth of field avialable in the particular device's optics and the pilots own eye's ability to focus over broad ranges of focus. You mentioned video of such a sight, this may be deceptive as the reticule is by the nature of it's projection in focus at a different lens setting to the glass and housing of the sight. If the camera in use is focused on the glass/housing and has a poor depth of field the reticule will be out of focus. The closer the camera is to the sight aparatus, the more out of focus the reticle will appear as long as the camera is set to focus on the glass/housing rather than the reticle.

Charos
08-29-2006, 08:54 PM
Originally posted by Tully__:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Charos:
...We now need to find out what physical ring size the Revi16B paints on the reflector glass...

Can't be done. The reticle is not projected on the glass, it is projected at infinity (or nearly so) and is reflected by the glass. It subtends a (nearly) constant angle to the viewer regardless of the distance of the viewer from the sight glass so the apparent size of the reticle in relation to the glass will vary depending on viewing distance. When the viewer is close to the glass the reticle will seem small in relation to the glass. As the viewer moves back, the reticle will appear to grow to fill the glass but will remain apparently the same size in relation to an object 100m or more away. </div></BLOCKQUOTE>

Something must have been done because the Ring size ingame has changed since early days. unlike reality we only have one fixed point where
we look into the gunsight, so the size ingame is always constant.
What you say about it projected at nearly infinity is what I understand to be true as well. My wording was rather basic but the result is a "painting" of the
ring on the reflector glass caused by reflection.

Back in July I posted about this fact here:

Forum Post (http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/2371068464?r=4031022564#4031022564)

"The very thing you mention was from memory a prime consideration when the optical sights were being designed to take over from the fixed iron sights.
I vaguely remember that the focal length is set near infinity so as the sight ring does not change with pilot eye distance.
This is done because the Sight is harmonised with the Guns for a certain fireing condition and then the sight is set for a particular target.
The last thing you want is the crossbars or other markers on the sight to provide a false idea of target distance.
The sight also focuses when the eye and sight are suitably aligned."

I guess here again I used poor wording and in hindsight even stuffed up on the sight ring size if taken literally.
At the time I can only think when I said "so as the sight ring does not change with pilot eye distance" was that if the pilot alters eye
distance the ring stays a proportional size with the target - so the RELATIVE size does not change yet even though you get an
APPARENT size change.

But It agree's with what you say about focus near infinity as well as stateing again about blurred sighting at incorrect distances.

Here is a picture I whipped up - because it says a thousand words and saves typing.

http://members.optusnet.com.au/~trentelliott/FW190/ReviEye.jpg



Originally posted by Tully__:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Charos:
I find the situation rather sad when Mods feel they need to move a thread of this nature from Oleg's Ready Room to the General discussion forum.

But they are content to leave untouched the following.

"Oleg, Plz model the MIG-28"

This topic clearly covers an outstanding issue with the game in question.
I don't get in ORR much but I do get in there enough to know that as far as the developers are concerned the Fw190 front view is a closed issue. ORR is there to discuss potential changes and bugs the developers may not be aware of. Oleg and his team are very well aware of this issue and all the evidence relating to it and it no longer has a place in ORR as they have clearly and repeatedly stated that they are not going to do anything about it and why. Consequently any thread relating to this issue for a long time and all future threads are being moved to general discussion (unless they slide into oblivion before being spotted by a moderator) to try & help with the clutter in ORR. </div></BLOCKQUOTE>

Then perhaps this should be added to the ORR forum posting criteria, I was not aware of this special ruleing.
Does this also apply to BOB or just IL2?
You also may not have noticed the Screen captures I posted of the FW190 these show that in the NON Gunsight views the pilots view is LOWER
than Gunsight view.

Is it not a bug when Gunsights IN GAME produce the following:

#1 FW190 Revi16b offset right - Normal view LOWER.
#2 BF109 Revi16b offset right - Normal view LOWER.
#3 JU87 Revi12D offset right - Normal view SAME as gunsight.
#4 ME163 Revi16b offset right - Normal view HIGHER .
#5 ME262 Revi16b offset right - Normal view ALOT HIGHER.
#6 Spifire 5 MK2 Centre - Normal view SAME as gunsight.
#7 Yak1b Centre - Normal view SAME as gunsight.

Why are AC ingame treated differently? The only two AC which have LOWER normal view than Gunsight view happen to be BF109 and FW190.
There maybe others as I have not tested everything.
Is this not an issue that is outstanding? or has this too been addressed.

The other issue which I have not yet raised is that the TA152 Gunsight is the ONLY Revi16b that is actually mounted close to the correct position
on the instrument panel. I have pictures to support this.
This issue is nothing to do with refraction but instead incorrect positioning of the Gunsight to begin with.

This topic covers several issues - they are all inter-related and to think it just deals with good old refraction is jumping the gun.


Originally posted by WWMaxGunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Tully__:
When the viewer is close to the glass the reticle will seem small in relation to the glass. As the viewer moves back, the reticle will appear to grow to fill the glass but will remain apparently the same size in relation to an object 100m or more away.

When I posted that I was told the reticle will blur. Thought I had it right.
It's a very good sight though. Beats lining up iron sites, tubes and such. </div></BLOCKQUOTE>

Max please see the picture I posted above - I will explain it further if required, or if rebutted will gladly change my stance.

Charos
08-29-2006, 09:07 PM
Rall

Kindly take your comments to the following thread in ORR I dont think comments like that are fit for the General forum.
Thankyou for your input. http://forums.ubi.com/images/smilies/clap.gif

MIG28 (http://forums.ubi.com/eve/forums/a/tpc/f/63110913/m/2161070574)

LStarosta
08-29-2006, 09:08 PM
ROFL!

Ali G in da house!

JG7_Rall
08-29-2006, 09:09 PM
Originally posted by Charos:
I find the situation rather sad when Mods feel they need to move a thread of this nature from Oleg's Ready Room to the General discussion forum.

But they are content to leave untouched the following.

"Oleg, Plz model the MIG-28"

This topic clearly covers an outstanding issue with the game in question.

There was tongue in cheek comments but nothing outlandish.

No matter I have other means open to me - But I
must say I find it sad the community cant openly discuss valid game issues on Olegs Forum.

Either close ORR or add the MIG28 http://forums.ubi.com/images/smilies/shady.gif to the game, I assume that posts validity must be more relevent.
And no moveing that post to General will not justify previous actions.
__________________________________________________ ___________________________
Purpose of Oleg`s Ready Room:

1) Dialog with the developer:

a) Questions regarding IL-2 series and future flight simulations.
b) Suggestions for current products and future line of products.
c) Personal questions €" but please, be reasonable

2) Bugs and possible inaccuracies reporting:

Bottom line:

Anything that doesn€t meet this criteria will be moved out to general discussion or deleted.

Also, from now on - Tagert, Buzzsaw, Gibbage and Maxgunz are not allowed to participate in the threads started by Kurfurts and in the same time, Kufurst is not allowed to participate in theirs. This is new rule, I just made that up in order to keep this place somewhat sane. Too many interesting threads were locked because of you guys... and you are the ones to blame. I hope we are clear on this one.

V!
Regards,


Why you hate
MiG two eight?

JG7_Rall
08-29-2006, 09:11 PM
Originally posted by Charos:
Rall

Kindly take your comments to the following thread in ORR I dont think comments like that are fit for the General forum.
Thankyou for your input. http://forums.ubi.com/images/smilies/clap.gif

MIG28 (http://forums.ubi.com/eve/forums/a/tpc/f/63110913/m/2161070574)

I'd say comments mine
are more fit than your MiG-hate swine!

LStarosta
08-29-2006, 09:16 PM
OH SNAP!

EMCEE NATE ROBE IN DA HAUS!

JG7_Rall
08-29-2006, 09:17 PM
what rhymes with Charos?

LStarosta
08-29-2006, 09:20 PM
dental floss?

JG7_Rall
08-29-2006, 09:22 PM
after post-talking with the great Charos
think i to recommend some dental floss!

Tully__
08-30-2006, 02:32 AM
Originally posted by Charos:
Max please see the picture I posted above - I will explain it further if required, or if rebutted will gladly change my stance.

The picture is wrong. When the eye is close to the sight, you will see the entire reticle with plenty of empty glass around it. It's when your eye is far away that the edges of the reticle will fall off the edges of the glass.


Why are AC ingame treated differently? The only two AC which have LOWER normal view than Gunsight view happen to be BF109 and FW190.
There maybe others as I have not tested everything. Different seating positions and dashboard heights will give different results. A very reclined seat and high dash may well result in the normal (non-gunsight) view being lower than the sight view as the pilot sits up to see through the sight. A slightly reclined seat when combined with a medium height dash will give normal and sight views at similar heighs and an upright seat combined with a low dash may result in a lower sight line than normal view line (unless the gunsight is mounted high above the dash and in a position such that the pilot doesn't need to lean forward much to get optimum viewing distance).

As the Bf109 and Fw190 both had seats that were significantly more reclined than most (all?) allied aircraft, it may well be correct to have the circumstances you describe but as I haven't studied blueprints and seating arrangements for any of the real life aircraft I'll not go so far as to say the view we have is definitely right or wrong in that regard.

WWMaxGunz
08-30-2006, 03:14 AM
Sight ring should appear same size always. You move your eye closer to the sight, does
the target appear smaller or larger? No. How wide does 10m look at 100m (one sight we
did have the ring was for 200m in original game and was corrected. I forget what plane.)
is how wide the ring should look. At normal FOV sizes are 1/4 real... but a scanned
picture can be resized a well. We fly TV's, not looking through windows.

Charos
08-30-2006, 05:40 AM
Originally posted by Tully__:
The picture is wrong. When the eye is close to the sight, you will see the entire reticle with plenty of empty glass around it. It's when your eye is far away that the edges of the reticle will fall off the edges of the glass.


Here are two pictures of what I am talking about. It shows a Revi-12D

The one with the smaller ring is taken with a large amount of zoom, you can tell Macro is not being used simply
by what is in focus and what isnt.
When a camera utilises zoom in the optical sense it increases the focal length - IE: the distance from Objective lense to
Film or CCD or whatever increases. This has the affect of oncreasing the apparent distance from the sight -IE: Light now has to travel further to get to the Film.
http://members.optusnet.com.au/~trentelliott/FW190/Revi12D_Distant.jpg

The other shot as you can see is not utilizing much if any zoom at all IE: Less focal length or in otherwords closer to the gunsight, as you can see the ring is not there. Not only is the ring not there you can now see how large the crosshairs have become.
http://members.optusnet.com.au/~trentelliott/FW190/Revi12D_Close.jpg


Why are AC ingame treated differently? The only two AC which have LOWER normal view than Gunsight view happen to be BF109 and FW190.
There maybe others as I have not tested everything. Different seating positions and dashboard heights will give different results. A very reclined seat and high dash may well result in the normal (non-gunsight) view being lower than the sight view as the pilot sits up to see through the sight. A slightly reclined seat when combined with a medium height dash will give normal and sight views at similar heighs and an upright seat combined with a low dash may result in a lower sight line than normal view line (unless the gunsight is mounted high above the dash and in a position such that the pilot doesn't need to lean forward much to get optimum viewing distance).

As the Bf109 and Fw190 both had seats that were significantly more reclined than most (all?) allied aircraft, it may well be correct to have the circumstances you describe but as I haven't studied blueprints and seating arrangements for any of the real life aircraft I'll not go so far as to say the view we have is definitely right or wrong in that regard.[/QUOTE]


All pilots are strapped into their respective seats very snuggly, if this were not the case they would end up in all sorts of grief under high G loading. The only thing they can do Sighting wise is roll their shoulders and dip their head.
Its not possible to alter seating position as such.

Here is an example of the change in height of the eyeline with head movement alone. A few inches at best - BUT the head is dipped for sighting view NOT normal view.
http://members.optusnet.com.au/~trentelliott/FW190/BarkhornD9.jpg

Charos
08-30-2006, 06:03 AM
Originally posted by WWMaxGunz:
Sight ring should appear same size always. You move your eye closer to the sight, does
the target appear smaller or larger? No. How wide does 10m look at 100m (one sight we
did have the ring was for 200m in original game and was corrected. I forget what plane.)
is how wide the ring should look. At normal FOV sizes are 1/4 real... but a scanned
picture can be resized a well. We fly TV's, not looking through windows.


Im tending to agree with you on the Size Max.

The standard human eye only has a focal length of 17mm whereas a Camera may have 400mm
focal length.

Not only that but the pilot simply cant move very far - he is strapped in and isnt going
anywhere in a hurry.

So for the human eye I imagine it wouldnt change much at all.

Here is the Optics system we are dealing with:

http://mezek.valka.cz/texty/letadla/revi16b/revi16b2.jpg

LStarosta
08-30-2006, 07:58 AM
They used AOL Instant Messenger in WWII?

BBB_Hyperion
08-30-2006, 09:03 AM
Originally posted by Tully__:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Charos:
I find the situation rather sad when Mods feel they need to move a thread of this nature from Oleg's Ready Room to the General discussion forum.

But they are content to leave untouched the following.

"Oleg, Plz model the MIG-28"

This topic clearly covers an outstanding issue with the game in question.
I don't get in ORR much but I do get in there enough to know that as far as the developers are concerned the Fw190 front view is a closed issue. ORR is there to discuss potential changes and bugs the developers may not be aware of. Oleg and his team are very well aware of this issue and all the evidence relating to it and it no longer has a place in ORR as they have clearly and repeatedly stated that they are not going to do anything about it and why. Consequently any thread relating to this issue for a long time and all future threads are being moved to general discussion (unless they slide into oblivion before being spotted by a moderator) to try & help with the clutter in ORR. </div></BLOCKQUOTE>

As we wait for BoB:SoW this things should be discussed before the FW Addon appears. Over the years lot of material has been posted and discussed. The decision for the il2 engine is understandable but cutting it off from newer projects is a little contraproductive. The place to make suggestions and discuss details of the sim should be ORR . If they were that aware then what is about the statement from Oleg that the FW will be excatly as it is now in BoB ?

What can be seen throughout the sim is that armored glass is modeled after blueprints but that is not a realistic reprensentation of the cockpit view . Before adepting this strategy for BoB there should be at least some concerns that Oleg can read when if he ever visits ORR again.

So i dont agree with this decision but have to live with it.

Such topics as 50s undermodeled with lot of ppl complaining did show a massive effect on the give in to whiners part. Same as the Mg151/20 with the infamous Mine Shell missing once it was in it was too strong now it is reduced again speaking of online only of course.

So when keeping such topics as this out of sight there is little doubt that there will be no change in the next sim.

Just my 0.02" http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Tully__
08-30-2006, 09:08 AM
Originally posted by Charos:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Tully__:
The picture is wrong. When the eye is close to the sight, you will see the entire reticle with plenty of empty glass around it. It's when your eye is far away that the edges of the reticle will fall off the edges of the glass.


Here are two pictures of what I am talking about. It shows a Revi-12D

The one with the smaller ring is taken with a large amount of zoom, you can tell Macro is not being used simply
by what is in focus and what isnt...
When a camera utilises zoom in the optical sense it increases the focal length - IE: the distance from Objective lense to
Film or CCD or whatever increases. This has the affect of oncreasing the apparent distance from the sight -IE: Light now has to travel further to get to the Film.
http://members.optusnet.com.au/~trentelliott/FW190/Revi12D_Distant.jpg

The other shot as you can see is not utilizing much if any zoom at all IE: Less focal length or in otherwords closer to the gunsight, as you can see the ring is not there. Not only is the ring not there you can now see how large the crosshairs have become.
http://members.optusnet.com.au/~trentelliott/FW190/Revi12D_Close.jpg </div></BLOCKQUOTE>
It's almost impossible to tell what I'm trying to explain from those pics because of the different zoom levels. In any case the light path within the camera is not relevant except that it affects the field of view angle that the picture includes. It will not change the relative size of the reticle in relation to the sight glass if both pics were taken from the same distance from the sight and the sight range and wingspan settings were the same in both pictures.

What has changed is the focus. In the first pic the camera is focused on the reticle image and the sight glass/body is out of focus. In the second pic the sight is in focus but the reticle is blurred. This makes it very difficult to tell accurately the apparent size of the reticle in relation to the sight glass in the second pic. It seems to me that the ring is still within the glass but is not visible in the photo due to the poor focus and the low intensity light source being used to illuminate the reticle (a pocket torch, looks like a single AAA cell battery model http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif). I've been posting from work but I'll try to do an image to show you how the area of the sight glass occupied by the reticle is affected by viewing distance when I get home.


All pilots are strapped into their respective seats very snuggly, if this were not the case they would end up in all sorts of grief under high G loading. The only thing they can do Sighting wise is roll their shoulders and dip their head.
Its not possible to alter seating position as such.

Here is an example of the change in height of the eyeline with head movement alone. A few inches at best - BUT the head is dipped for sighting view NOT normal view.
[ IMG]http://members.optusnet.com.au/~trentelliott/FW190/BarkhornD9.jpg[/IMG] I take your point and refer you back to my disclaimer ("...but as I haven't studied blueprints and seating arrangements for any of the real life aircraft I'll not go so far as to say the view we have is definitely right or wrong in that regard...") but will point out that this photo is also not much use as the attitude of the aircraft (landed) has caused the pilot to adopt a very un-natural posture.

Charos
08-30-2006, 09:49 AM
After looking at the internal Revi optics again I think I now have a theory as to why it does what it does.

Tully as you mentioned before the sight ring should get larger with eye distance from the sight - if this matched the correspnding shrink you get with range then the ring stays a constant size.

There is only one possible way I can think of that this would take place, but its getting late and I will have another think about it in the morning.
Up until now I have been looking at the sight as if it functioned like a newtonian reflector telescope - but it may have a slight trick that sets it apart.


Interesting you mention that Barkhorn is in an unnatural position.
His seating seems normal - he simply has his head turned and dipped down.
What else is amiss with his posture?

BBB_Hyperion
08-30-2006, 10:49 AM
Charos that is not the inflight seating position this why i would disqualify most ground pictures nor it is the gunsight position. Further seat cushion used or not (seems like no fligthjacked , parachute on etc)?

faustnik
08-30-2006, 10:54 AM
Originally posted by BBB_Hyperion:
Charos that is not the inflight seating position this why i would disqualify most ground pictures nor it is the gunsight position. Further seat cushion used or not (seems like no fligthjacked , parachute on etc)?

I think that is the reason for a lot of confusion with the Fw190 forward view.

Manu-6S
08-30-2006, 11:00 AM
Originally posted by Charos:
Interesting you mention that Barkhorn is in an unnatural position.
His seating seems normal - he simply has his head turned and dipped down.
What else is amiss with his posture?

We have dozen of images: in some the head is lower inside the cockpit in other the heads are high as the canopy.

http://img217.imageshack.us/img217/3760/fw19044ke8.jpg

http://img171.imageshack.us/img171/68/fw190a37xk6.jpg

http://img239.imageshack.us/img239/2114/fw190a435ig7.jpg

Which is the really position? Surely the position of a inflight pilots is more credible.

http://img74.imageshack.us/img74/8362/gunsightnl1.jpg

BBB_Hyperion
08-30-2006, 11:29 AM
Originally posted by Manu-6S:
We have dozen of images: in some the head is lower inside the cockpit in other the heads are high as the canopy.

http://img217.imageshack.us/img217/3760/fw19044ke8.jpg


Look at cap no pilot a technican no seat cushion


Originally posted by Manu-6S:

http://img171.imageshack.us/img171/68/fw190a37xk6.jpg


Correct Leatherheadset and backpack with seatcushion.


Originally posted by Manu-6S:
http://img239.imageshack.us/img239/2114/fw190a435ig7.jpg
Which is the really position? Surely the position of a inflight pilots is more credible.


Technician without backpack look at cap


Originally posted by Manu-6S:
http://img74.imageshack.us/img74/8362/gunsightnl1.jpg



Inflight Pilot wears correct leatherheadset and backpack with seatcushion.

So only 2 valid pictures http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Manu-6S
08-30-2006, 01:18 PM
Originally posted by BBB_Hyperion:
Inflight Pilot wears correct leatherheadset and backpack with seatcushion.

So only 2 valid pictures http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

I know, I was answering to this:
http://members.optusnet.com.au/~trentelliott/FW190/190IL2_View.jpg

But I would take only the inflight picture http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Charos
08-30-2006, 08:00 PM
Originally posted by faustnik:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BBB_Hyperion:
Charos that is not the inflight seating position this why i would disqualify most ground pictures nor it is the gunsight position. Further seat cushion used or not (seems like no fligthjacked , parachute on etc)?

I think that is the reason for a lot of confusion with the Fw190 forward view. </div></BLOCKQUOTE>

I agree guys - The sig pic is just a subtle bit of humour You may notice the occupant craining his neck up to see over the upper deck, I also added an insignia for the blind (he has a white cane).
Even though its on the ground it represents "Flying Blind".

Charos
08-30-2006, 09:51 PM
Ok as promised here is the updated diagram:
http://members.optusnet.com.au/~trentelliott/FW190/ReviNew.jpg

I think this now accounts for all the variables that have been raised.

The biggest issue I had was trying to get a handle on was the distant zoomed camera image being the inverse of a distant human eye.
I think this now covers that as well and aligns up with Tully's observations, and by enlarge starts to make more sense.

On the blurring of the reticle this can still be accounted for with large eye relief by the resolving capabilities of the human eye, not that this would probably be a factor in real life as that relief may not be possible in the practical sense.

But as the eye is taken further away from an object (in this case an iluminted sight) the light will begin to diverge.
At some distance the eye/brain no longer being able to correct for a sharp line, it will begin to blur.

But yes thats all well and good but does not shed any light on the previous issues raised regarding normalised view's being lower in certain AC as opposed to others.

We still have no concrete evidence why this is treated as it is ingame.

Tully__
08-30-2006, 11:00 PM
Diagram is still wrong. The reticle does not appear to the camera or the eye to be on the sight glass. It appears to be quitle a long distance (approximately infinity, actually only a few hundred metres) behind the glass. This is why the reticle and glass are not in focus at the same time. Like this:

http://jennirivers.actewagl.net.au/reticle.jpg

Zooming the camera will make no difference to how much of the sight glass is filled by reticle, only moving the camera or eye will change it. What zoom does change is how much of the surrounding scenery is included in the picture.

At position 1 the reticle occupies only a small part of the glass. As the eye moves back the reticle fills more of the glass until at position 3 the edges of the reticle are outside the edges of the glass (and not visible to the eye/camera).

It's the same principle as looking at a large building through a small window. You have to be close to the window to see the whole building. If you're using a camera zooming in wont change how much of the building appears in the window, if you can't see all of it you have to move the camera/eye closer to the window.


Edit: BTW you mentioned in an earlier post that the human eye has a focal length of 17mm... it's actually more like 50mm, which is why the "standard" lens on most SLR cameras is 50mm. The resulting picture are the most naturally appearing in terms of optical distortion and depth of field to humans because the image is made with a similar focal length to our natural equipment. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Charos
08-30-2006, 11:30 PM
Originally posted by Tully__:
Edit: BTW you mentioned in an earlier post that the human eye has a focal length of 17mm... it's actually more like 50mm, which is why the "standard" lens on most SLR cameras is 50mm. The resulting picture are the most naturally appearing in terms of optical distortion and depth of field to humans because the image is made with a similar focal length to our natural equipment. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

The Human Eye (http://clarkvision.com/imagedetail/eye-resolution.html)

""The most commonly purchased lens is a normal lens. Its focal length is about 50 mm. A normal lens is popular because it has the same perspective as the human eye."


The Focal Length of the Eye

Object focal length of the eye = 16.7 mm
Image focal length of the eye = 22.3 mm

The object focal length is for rays coming OUT OF THE EYE. But for an image on the retina, the image focal length is what one wants. E.g. see: http://galileo.phys.virginia.edu/classes/531.cas8m.fall04/l11.pdf.

So this explains the commonly cited ~17mm focal length, but the correct value is ~22 mm focal length

This then makes more sense for the f/ratio: with an aperture of 7 mm, the f/ratio = 22.3/7 = 3.2.


As for the Diagram being incorrect I will get back to you on that but your Diagram and mine are similar. My initial diagram showed the reticle on the glass but my latest does not. Its REFLECTED rather than PROJECTED in free space.
Hence the name of the sight "Reflector" not "Projector" Gunsight.

Tully__
08-31-2006, 12:44 AM
Originally posted by Charos:
As for the Diagram being incorrect I will get back to you on that but your Diagram and mine are similar. My initial diagram showed the reticle on the glass but my latest does not. Its REFLECTED rather than PROJECTED in free space.
Hence the name of the sight "Reflector" not "Projector" Gunsight.

For the purposes of how the image appears to the viewer the difference is irrelevant. From the viewer's perspective, an image in a mirror is optically indistinguishable from an image projectecd in real space. In order to understand the reticle behaviour you must imagine it as a 10m diameter ring and cross hanging in free space with its centre at guns' convergance location and imagine the reflector glass as a window through which you must look to see the reticle. If you imagine it that way you will understand every aspect of how it appears to the pilot.

Charos
08-31-2006, 12:55 AM
Originally posted by Tully__:
Diagram is still wrong. The reticle does not appear to the camera or the eye to be on the sight glass. It appears to be quitle a long distance (approximately infinity, actually only a few hundred metres) behind the glass. This is why the reticle and glass are not in focus at the same time. Like this:

http://jennirivers.actewagl.net.au/reticle.jpg

Zooming the camera will make no difference to how much of the sight glass is filled by reticle, only moving the camera or eye will change it. What zoom does change is how much of the surrounding scenery is included in the picture.

At position 1 the reticle occupies only a small part of the glass. As the eye moves back the reticle fills more of the glass until at position 3 the edges of the reticle are outside the edges of the glass (and not visible to the eye/camera).

It's the same principle as looking at a large building through a small window. You have to be close to the window to see the whole building. If you're using a camera zooming in wont change how much of the building appears in the window, if you can't see all of it you have to move the camera/eye closer to the window.



I agree with you that the APPARENT position of the reticle appears to be projected beyond the glass. This is what fools
the human eye into seeing a different perspective at distance between the Gunsight and the Reticle.

My diagram shows how this is done.


The optical system in a camera when zoomed has narrow FOV as compared to un-zoomed.
Because it has a norrow FOV it only see's the projected light reticle closer to the reflector plate than you
would with wider FOV. This is why it see's a smaller circle.
The camera thinks the circle is further away.

Thats how I see it at least.

Charos
08-31-2006, 01:20 AM
Originally posted by Tully__:
For the purposes of how the image appears to the viewer the difference is irrelevant. From the viewer's perspective, an image in a mirror is optically indistinguishable from an image projectecd in real space. In order to understand the reticle behaviour you must imagine it as a 10m diameter ring and cross hanging in free space with its centre at guns' convergance location and imagine the reflector glass as a window through which you must look to see the reticle. If you imagine it that way you will understand every aspect of how it appears to the pilot.

As long as the object exhibits reflection symmetry then yes your right. Which in our case it does.

Yes I understand about the 10M reticle at 100M in free space - that is what the pilots brain and eye see's but not actually what IS.

Its an illusion trick - the way it is done is what happens between the Revi and the pilot not the Revi and the outside world.

Tully__
08-31-2006, 02:04 AM
Originally posted by Charos:
The optical system in a camera when zoomed has narrow FOV as compared to un-zoomed.
Because it has a norrow FOV it only see's the projected light reticle closer to the reflector plate than you
would with wider FOV. This is why it see's a smaller circle.
The camera thinks the circle is further away.

Thats how I see it at least.
The change in zoom level changes the size of the picture as a whole but it doesn't change the relative size of the picture elements if the camera is in the same location for all zoom levels. If the reticle occupies 70% of the sight glass with zoom set to 17mm focal length it will still occupy 70% of the sight glass with zoom set to 200mm or 1500mm focal length. The only things that change with zoom are apparent size of the overall image as a whole and the apparent depth of the image. The relative size of objects in the image is determined by the relative angular dimensions of the objects as seen from the camera/eye and this doesn't change with zoom level.

Charos
08-31-2006, 07:30 PM
Sorry for the delay - RL interviened. http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif


Originally posted by Tully__:
The change in zoom level changes the size of the picture as a whole but it doesn't change the relative size of the picture elements if the camera is in the same location for all zoom levels. If the reticle occupies 70% of the sight glass with zoom set to 17mm focal length it will still occupy 70% of the sight glass with zoom set to 200mm or 1500mm focal length. The only things that change with zoom are apparent size of the overall image as a whole and the apparent depth of the image. The relative size of objects in the image is determined by the relative angular dimensions of the objects as seen from the camera/eye and this doesn't change with zoom level.


Under NORMAL circumstances your 100% right the perspective or relative size of all objects change in the same proportion.
This happens because the objects are FIXED in 3D space. this is not the case with the illuminated ring - it has no fixed address in 3D space.

We have already agreed on the fact and we know that the Reflector gunsight does not follow this rule in regards to the APPARENT size of the reticle.

As your eye (an optical system with objective cornea and focal plane IE: optic nerve) changes distance from the Revi - the reflected image APPEARS to grow larger.
Your Eye has been decieved simply because in actuality the illuminated image stays exactly the same size.
The APPARENT gain in size of the ring is due to your change in eye relief.
Now that you have moved away from the sight, perspective kicks in and the whole reflector plate now appaears smaller.

So this is what happens.

#1 Eye close = small ring size relative to reflector plate.
#2 Eye distant = larger ring size relative to reflector plate.

In both cases all we have done is move the optical sensing system (the eye) further from the gunsight. Our FOV stays exactly the same in both cases.

Now lets throw in a camera in the same position our eye was in #2 above IE: distant.

Firstly we have our camera unzoomed and tuned to the same FOV of our distant eye - the camera see's exactly what our eye does.
And why wouldnt it the physical conditions are the same.

Now lets begin to zoom the gunsight in, all the while maintaining our distant camera position.

What happens is the Camera FOV gets SMALLER.
The light that is reflected off the Gunsight is EXACTLY Parallel IE: The projected image stays the same size in 3D space projecting
back towards the viewing system.

With a smaller FOV you no longer can see the projected image near to the camera. The smaller field of view intercepts the illumiated image
much closer to the gunsight.

Just as you no longer see peripheral objects, you also no longer see the projected image close to the camera.

This has the affect of making the apparent illuminated ring smaller relative to the gunsight or in actuality just like it was in #1 above.

WWMaxGunz
08-31-2006, 07:55 PM
First, when I look through a sight, I am focussing on the TARGET, not the sight.

Second, Charos go back to that place and take a blank index card (the back of a lined one)
with a few concentric boxes printed on it, small to large like 5mm, 1cm, etc.

Get the Revi set solid with the light and hold the card back from it so the light falls on it.
Shade the card from most other light but leave enough to see the squares and see how the circle
lines up inside any square exactly as you can and then what trend you get as you move the card
back and forth.

I think that you WILL be surprised or nah, I'll spoil it for you. The farther away my eye gets
from Revi, the smaller the angle my eye is to the Revi. Compreni-vous? Directed light is not
the same as reflected light from an object, after all.

Xiolablu3
08-31-2006, 08:07 PM
I love the FW190, its my favourite plane at the moment.

But I cant help thinking that the forward view looks pretty much correct fromt he pics I have seen (of course I have never sat in one, so my opinon doesnt mean a lot)

But pics like this one

http://members.optusnet.com.au/~trentelliott/FW190/BarkhornD9.jpg

He sure looks like he would have a very poor forward view over the nose looking at the pic and placement of the control panel/Revi.

Just my thoughts.

Xiolablu3
08-31-2006, 08:14 PM
Originally posted by WWMaxGunz:


So the head position is not off, spend some time doing the geometry on a scale drawing to
maybe figure out that if you raise your eye and look through the center of the glass then
you will get an even worse view over the nose.


This sounds correct to me, although couldnt the revi be adjusted for different pilots heights?? Or was it fixed?

If it was fixed, then making your head higher would make the Revi view even worse.

Kettenhunde
08-31-2006, 08:19 PM
The seat is adjustable in height guys.

All the best,

Crumpp

Jaws2002
08-31-2006, 08:22 PM
If the game designer wants to get it right, he can.


http://img.photobucket.com/albums/v258/<FA>Jaws/190.jpg

Charos
08-31-2006, 08:23 PM
Yes Max.
Perhaps this may explain it more clearly.
Reflector Operation (http://www.eugeneleeslover.com/USNAVY/CHAPTER-16-F.html)

"Figure 16F4 represents the optical system of a lead-computing sight using a single gyro. The two windows seal the instrument to keep out dust and moisture. The system does not magnify the target image. The operator observes the target directly, through the two windows and the clear reflecting glass. The lamp at the top of the diagram is used to illuminate the reticle. The reticle is located exactly at the focal point of the collimating lens. Rays of light from the reticle are therefore parallel after they pass through the lens, and after they are reflected toward the operator by the reflecting glass. Because these rays are parallel, the reticle image appears to lie at infinity, and the reticle will not change its apparent direction when the operator moves his head from side to side.

Charos
08-31-2006, 08:29 PM
Originally posted by Kettenhunde:
The seat is adjustable in height guys.

All the best,

Crumpp

Yep thats indeed another Factor Crumpp. http://forums.ubi.com/images/smilies/25.gif

As has been often said - the whole issue revolves around a great many factors, least of all refraction.

I cant see how refraction provides much more that approx 16mm of vertical height gain.

On refraction its not been mentioned but its fair to say that Sighting view goes through DOUBLE Refraction,
Once on the 50mm armour glass and again on the Gunsight which is probably 45Deg at about 10mm thick.

WWMaxGunz
08-31-2006, 08:40 PM
Originally posted by Charos:
Yes Max.
Perhaps this may explain it more clearly.
Reflector Operation (http://www.eugeneleeslover.com/USNAVY/CHAPTER-16-F.html)

"Figure 16F4 represents the optical system of a lead-computing sight using a single gyro. The two windows seal the instrument to keep out dust and moisture. The system does not magnify the target image. The operator observes the target directly, through the two windows and the clear reflecting glass. The lamp at the top of the diagram is used to illuminate the reticle. The reticle is located exactly at the focal point of the collimating lens. Rays of light from the reticle are therefore parallel after they pass through the lens, and after they are reflected toward the operator by the reflecting glass. Because these rays are parallel, the reticle image appears to lie at infinity, and the reticle will not change its apparent direction when the operator moves his head from side to side.

Parallel.
So the circle will get neither larger nor smaller with distance from the glass.

WWMaxGunz
08-31-2006, 08:44 PM
Originally posted by Kettenhunde:
The seat is adjustable in height guys.

All the best,

Crumpp

And the virtual pilot is one size. Seat is adjusted for putting eye in line with Revi?

Tully__
08-31-2006, 08:51 PM
Originally posted by Charos:
...stuff about optics...
That is not the case. The whole point of a reflector sight is that the image of the reticle is optically indistinguishable from a physical ring and cross placed in the same location as the image appears. As far as the camera and the eye are concerned the reticle and a physical replica placed in the same apparent location would behave identically. I'm at work again so you're going to have to wait for another diagram until tomorrow.

You're correct that there are optical illusions associated with how a pilot interprets what he sees, but all that I've said so far is correct. The proportion of the sight glass filled by the reticle is the same on the retina as it is in the camera image plane if they're viewing at the same distance from the sight glass regardless of the zoom setting / focal length of the camera lens.

Kettenhunde
08-31-2006, 09:03 PM
This is a very crude approximation I did with paint and Vespa's game.
http://img40.imagevenue.com/loc387/th_79221_view_from_the_pit_122_387lo.JPG (http://img40.imagevenue.com/img.php?image=79221_view_from_the_pit_122_387lo.JP G)

This is closer to the view over the nose. You can clearly see the top of the waffenhaube when sitting in the cockpit. You cannot see any portion of the lower armored glass mounting frame.

The general lines of the framing are off somewhat in that picture but you get the idea. It is just a tad too high. The side glass is way off too.

Here are the sight settings. The black triangle is the point of aim for the Revi sight.
http://img44.imagevenue.com/loc537/th_79228_190_gun_2_122_537lo.jpg (http://img44.imagevenue.com/img.php?image=79228_190_gun_2_122_537lo.jpg)

All the best,

Crumpp

Charos
08-31-2006, 09:23 PM
Originally posted by WWMaxGunz:
So the circle will get neither larger nor smaller with distance from the glass.


Originally posted by Charos:

What happens is the Camera FOV gets SMALLER.
The light that is reflected off the Gunsight is EXACTLY Parallel IE: The projected image stays the same size in 3D space projecting
back towards the viewing system.



Max either im writing in another language or your not reading what im writing. http://forums.ubi.com/images/smilies/blink.gif

LStarosta
08-31-2006, 09:26 PM
LoL...

Here's an idea...

Put a sheet of paper with a crosshairs drawn in high contrast, and put it on your dash face up.

Then, get on the highway and start shooting down mofo's using the cruise control keys on your steering wheel.

Charos
08-31-2006, 10:00 PM
Originally posted by Tully__:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Charos:
...stuff about optics...
That is not the case. The whole point of a reflector sight is that the image of the reticle is optically indistinguishable from a physical ring and cross placed in the same location as the image appears. As far as the camera and the eye are concerned the reticle and a physical replica placed in the same apparent location would behave identically. I'm at work again so you're going to have to wait for another diagram until tomorrow.

You're correct that there are optical illusions associated with how a pilot interprets what he sees, but all that I've said so far is correct. The proportion of the sight glass filled by the reticle is the same on the retina as it is in the camera image plane if they're viewing at the same distance from the sight glass regardless of the zoom setting / focal length of the camera lens. </div></BLOCKQUOTE>


Ok Tully your a tough not to crack http://forums.ubi.com/images/smilies/11.gif - here goes another way of looking at it.


Grab a piece of paper - draw two lines Parallel to each other (this represents the reflected illuminated outer sight ring.

At one end of the parallel lines put in a wider box - representitive of the larger reflector glass.

Now stick an eye in between the parallel lines - anywhere you want.

Now draw two FOV arcs from the eye - one at say 60 Deg and the other at 20 Deg.

Hopefully you will draw them in such a way that both FOV's show the entire Reflector glass box.

Now - see where each FOV line BISECTS the parallel lines?

On the large (60 FOV) the lines are biscted closer to the eye.

On the small (20 FOV) the parallel lines are bisected further from the eye

You should notice a few things:

#1 The Reflector glass fills the entire 20 Deg field of view.

#2 The reflector glass fills a much smaller proportion in the 60 Deg field of view.

#3 In both cases the Gunsight ring is the same size this is because while the reflector glass has not moved - the illuminated ring apparently has.

BBB_Hyperion
08-31-2006, 10:30 PM
Originally posted by Charos:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
The seat is adjustable in height guys.

All the best,

Crumpp

Yep thats indeed another Factor Crumpp. http://forums.ubi.com/images/smilies/25.gif

As has been often said - the whole issue revolves around a great many factors, least of all refraction.

I cant see how refraction provides much more that approx 16mm of vertical height gain.

On refraction its not been mentioned but its fair to say that Sighting view goes through DOUBLE Refraction,
Once on the 50mm armour glass and again on the Gunsight which is probably 45Deg at about 10mm thick. </div></BLOCKQUOTE>

For the armour glass i did once a calculation. Assuming 25 degrees Alpha 1,0 Index for Air and 1,6 Index for Glas(Armored glass has higher index) and came out at about 3 cm shifting from outside horizontal ray to inside position this was without reflector inside.

Dont know where i got the 25 degrees from . But on Blueprint is 65 from estimate (90-65)=25 so seems to fit.

http://img158.imagevenue.com/loc390/th_84994_fwglassangle_122_390lo.jpg (http://img158.imagevenue.com/img.php?image=84994_fwglassangle_122_390lo.jpg)

Charos
08-31-2006, 10:40 PM
Originally posted by Kettenhunde:
This is a very crude approximation I did with paint and Vespa's game.
http://img40.imagevenue.com/loc387/th_79221_view_from_the_pit_122_387lo.JPG (http://img40.imagevenue.com/img.php?image=79221_view_from_the_pit_122_387lo.JP G)

This is closer to the view over the nose. You can clearly see the top of the waffenhaube when sitting in the cockpit. You cannot see any portion of the lower armored glass mounting frame.

The general lines of the framing are off somewhat in that picture but you get the idea. It is just a tad too high. The side glass is way off too.

Here are the sight settings. The black triangle is the point of aim for the Revi sight.
All the best,

Crumpp


Your FW190 ballistics diagram shows 15.1CM Revi pipper height above MG131 centre line.

Yes the Cockpit coaming would drift further down with higher view and be less obstructive to the side panels.

There is another factor that relates to seating view on the ground as opposed to in the air that I will now attempt to describe.


When the FW190 sits on the deck the elevation angle of the nose is some 13 Deg (From info I have, may not be accurate).

The AC rotates attitude as it takes off to flight attitude.

This can be thought of like a playground seesaw.


The main undercarriage is the seesaw Fulcrum point about which the AC rotates.

Points to note.

#1 Fulcrum point is ahead of cockpit.
#2 Cockpit instrument panel and gunsight is 500mm or more forward of pilot. (again rough figures)

What this means on the deck is that because the pilot is further back from the Fulcrum than the instrument panel his vertical height is lower.

As an example with the above quoted figures (500 * Tan 13) = 115mm Vertical height.

Therefore if the pilot on the ground was to look straight ahead parallel to the ground his view is 115mm lower than inflight attitude.

Which is demonstated aptly by the fellow in my Sig Pic.

Tully__
08-31-2006, 11:20 PM
Originally posted by Charos:

Ok Tully your a tough not to crack http://forums.ubi.com/images/smilies/11.gif - here goes another way of looking at it.


Grab a piece of paper - draw two lines Parallel to each other (this represents the reflected illuminated outer sight ring.

At one end of the parallel lines put in a wider box - representitive of the larger reflector glass.

Now stick an eye in between the parallel lines - anywhere you want.

Now draw two FOV arcs from the eye - one at say 60 Deg and the other at 20 Deg.

Hopefully you will draw them in such a way that both FOV's show the entire Reflector glass box.

Now - see where each FOV line BISECTS the parallel lines?

On the large (60 FOV) the lines are biscted closer to the eye.

On the small (20 FOV) the parallel lines are bisected further from the eye
Unfortunately that's not how to resolve the image. That analysis assumes that light is changing direction mid path. While all light from a given point on the reticle is parallel (or very close to) after passing through the collimater lens, light from one point on the reticle is not parallel to light from a different point on the reticle after passing through the collimater lens. If what you describe were the case you wouldn't see a clearly defined reticle when you looked through the sight, instead you'd see a pinpoint light source.

If I get time over the weekend I'll whip up a full light path diagram to show you how it works.

Xiolablu3
09-01-2006, 04:41 AM
Originally posted by Kettenhunde:
The seat is adjustable in height guys.

All the best,

Crumpp

WHat about the Revi Sight, Crump? Is that adjustable for height?

As WWMAxguns said, if you just make your seat higher, then the Revi will actually appear LOWER.

Can you move the Revi up and down for different peoples heights?

Sorry if this is a dumb question, I have never seen a real REVI sight.

Kettenhunde
09-01-2006, 04:51 AM
WHat about the Revi Sight, Crump? Is that adjustable?


The sight itself is adjustable for windage and elevation. There is no adjusment on the mounting hardware however outside of that AFAIK.
http://img19.imagevenue.com/loc340/th_08606_revi4_122_340lo.jpg (http://img19.imagevenue.com/img.php?image=08606_revi4_122_340lo.jpg)

However the reality is that lowering your head to line up a shot is just not that hard.

All the best,

Crumpp

Charos
09-01-2006, 05:27 AM
Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">WHat about the Revi Sight, Crump? Is that adjustable?


The sight itself is adjustable for windage and elevation. There is no adjusment on the mounting hardware however outside of that AFAIK.

However the reality is that lowering your head to line up a shot is just not that hard.

All the best,

Crumpp </div></BLOCKQUOTE>

On the Revi-16B the line of sight can be adjusted +/-2.5 Deg horizontally and +/-3 Deg vertically.

As crump said lowering your head isnt that hard. A few inches can be achieved without issue.

So in other words the Revi-16B has more positive vertical adjustment than we have in total
gunsight view from pipper to bar.

Xiolablu3
09-01-2006, 07:17 AM
Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">WHat about the Revi Sight, Crump? Is that adjustable?


The sight itself is adjustable for windage and elevation. There is no adjusment on the mounting hardware however outside of that AFAIK.
http://img19.imagevenue.com/loc340/th_08606_revi4_122_340lo.jpg (http://img19.imagevenue.com/img.php?image=08606_revi4_122_340lo.jpg)

However the reality is that lowering your head to line up a shot is just not that hard.

All the best,

Crumpp </div></BLOCKQUOTE>

Ok thanks for the info mate.

I was just thinking that if there was adjustment for height, then you could make the sight appear higher on the windscreen.

WWMaxGunz
09-01-2006, 09:17 AM
............

Charos please mark a card or paper with squares and illuminate it with that Revi if the trip
is not to far? Take the pictures of that. Nothing like actual results and then to explain
eye workings don't really matter. What you see looks like the same size coming from the glass
because it is light reflected from that part of the glass.

-------------------

FW flies "nose down" yeah but the line through the Revi also rotates down with the nose.

Sure you can adjust elevation of the sight but the guns will fire the same as before.
The sight points where the plane is going and the guns point higher since shells do drop as
they move forward. Elevation is just correcting sight line for range or non-standard firing
conditions that I don't think was done... deflection is something judged off-hand.

Manu-6S
09-01-2006, 09:53 AM
Originally posted by Kettenhunde:
However the reality is that lowering your head to line up a shot is just not that hard.

Magic words. http://forums.ubi.com/images/smilies/25.gif

Tully__
09-02-2006, 09:45 PM
Here we go:


http://jennirivers.actewagl.net.au/reflect.jpg


Solid blue shows actual light path. The camera/eye interprets the light by tracing in a straigh line back to intersect points as shown by the dashed blue lines. This determines where the apparent location of the reticle appears to the camera/eye. Moving the actual reticle closer to the focal plane of the collimator lens in the sight moves the apparent location of the reticle further away and makes it's apparent size bigger, moving the actual reticle closer to the lens brings the apparent location closer to the sight glass and brings the apparent size closer to the actual reticle size. This corresponds to the range setting available to pilots in some types of reflector site.

By the addition of some extra lens assemblies within the sight the apparent size of the reticle can be changed without moving the apparent location. These extra lenses are what is being adjusted when the pilot changes the wingspan/target type setting available on some types of reflector sight.

The mucky blue green and the light green lines show respectively approx 90 degree FOV (roughly human eye) and approx 30 degree FOV (roughly 150mm telephoto/zoom lens). The orange and yellow lines show respectively the apparent angular size of the sight glass and reticle. The relationship between these two angles determines the apparent size of the reticle in relation to the sight glass. As can be seen here, the change in zoom would have absolutely no effect on the relationship between those two angles, but moving the eye/camera toward or away from the sight does change the relationship. Further, changing the zoom level doesn't change the real or apparent light paths that determine where the reticle image appears. Only adjustments in the relationship between the physical reticle within the sight, the collimator lens and the focal length of the collimator lens can affect the apparent location of the reticle image. Only those adjustments and the adjustments of those factors and adjustments to any additional lens elements that may be within the site can affect the actual size (as distinct from the angular size) of the reticle image.

Charos
09-03-2006, 11:54 PM
Firstly, Very nice drawing Tully lots of detail there. http://forums.ubi.com/images/smilies/25.gif

Secondly Im going to Quote the previously posted article on the operation of a Reflector sight but this time in point form:


"Figure 16F4 represents the optical system of a lead-computing sight using a single gyro. The two windows seal the instrument to keep out dust and moisture.


#1 The system does not magnify the target image.

#2 The operator observes the target directly, through the two windows and the clear reflecting glass.

#3 The lamp at the top of the diagram is used to illuminate the reticle.

#4 The reticle is located exactly at the focal point of the collimating lens.

#5 Rays of light from the reticle are therefore parallel after they pass through the lens, and after they are reflected toward the operator by the reflecting glass.

#6 Because these rays are parallel, the reticle image appears to lie at infinity, and the reticle will not change its apparent direction when the operator moves his head from side to side."



Note points #4, #5 and #6.

Now with that in mind look at the following.


"The Collimator is an optical instrument consisting of a well corrected objective lens with an illuminated reticle at its focal plane. The emerging beam is parallel (collimated beam), so that the image of the reticle is projected at infinity. The collimator is usually set up in this way known as infinity adjustment (setting).

When moving the reticle out of the focal plane of the objective lens, the shape of the emerging beam will change:

* Moving the reticle away from objective lens will result in a convergent beam. The image of the reticle is real and projected at a finite distance.
* Moving the reticle toward the objective lens will result in a divergent beam. If the beam diverges, a virtual image is produced at the aparent crossing point of the beam rays. This point is also located at a finite distance. This adjustment of the collimator is known as finite distance setting."

http://www.mildex.com/images/testequip/optitest/otest01.gif

You will note there are 3 different types of collimation mentioned.
The most common form is mentioned in the top picture - this also is in agreement with points #4, #5 and #6 above.
The bottom picture represents a divergent form which is representitive of what you have in your picture.


There are two main things to note on your diagram.

#1 The light from the reticle is DIVERGENT.

#2 Reticle light swaps sides due to divergent beam.


Because the light is divergent it has a FINITE focal range (see diagram) thats why its labelled "Finite distance setting."
This means there is a very limited focal range just as in the middle "Finite distance setting - real image"

The reason is the inverse to the real image (middle senario).

Your eye can only view light that enters the objective lens - In your picture this is fine with Small eye relief but at greater relief the Divergent light can no longer be seen.
IE: Two laser pointers parallel and very close you will see both laser dots - now seperate the two beams by an angle. Your eye can see the dots up close but as they diverge you can no longer see them as the light falls outside your objective lens.

Because the light crosses path in your example this has the following affect.

When you do that you essentially INVERT the image which if your eye is exactly centered does Nothing.
BUT if you move your eye to the right - the image moves to the left and vise versa.

We know this is Not the case as the Reflected image follows the observers view to enshore correct line of sight.

karost
09-04-2006, 01:14 AM
Well ... this is the best topic to share a good value of knowledge to the community.


with gentle style and deep of knowledge and info that is the way for community like to read.

thanks Charos, Tully__ and other friends please keep going.

http://forums.ubi.com/images/smilies/11.gif
S!

Tully__
09-04-2006, 01:37 AM
If the reticle were placed at the focal plane it would appear infinitely large to the viewer. As we know for normal adjustment ranges it appears to have a ring about the same diameter as the wingspan of a fighter plane at 100-200m (depending on sight setting) and this is clearly NOT infinitely large it must not be at the focal plane (though as the magnification is very large it must be very close to the focal plane).

Further, as the apparent location of the image is a greater distance from the eye than the lens (never mind that the light has been bent by the mirror, if you took the mirror out of the equation and looked directly into the top of the sight the image would be the same) it is apparant that the image is virtual as it is on the same side of the lens as the object (reticle) so the reticle must be between the focal plane and the lens.

You misinterpreted the "light rays" drawn in light path diagrams. They are not the only light leaving the reticle. Light leaves the reticle with equal intensity in all directions, I have simply shown two of those directions from two points on the reticule to demonstrate the effects of the lens (and my drawing is by no means to scale either). There are lots of other light "beams" travelling between those drawn but not shown for the sake of clarity. You might find it's better explained at Wikipedia's article on Lens optics (http://en.wikipedia.org/wiki/Lens_%28optics%29)

I chose the scale I did so I could get all the lines in without making it too confusing, if I were to put all the objects at scale sizes and distances a PC screen doesn't have enough resolution to show what's happening at the reticle or the eye.

In a practical example if the image were at 200m range with 10m diameter and the reticle were 100mm behind the collimating lens the actual reticle diameter in the simple optical arrangement I've shown would have to be:

100mm/200000mm x 10m = 5mm

As the reticle image in the diagram is only about 60 pixels high, the reticle in the sight in the diagram would have to be less than one pixel (0.03 pixels to be exact) to be in scale. Edit: as an aside, using these figures the focal length would be approximately 100.05mm, so the reticle is VERY close to the focal plane.

Real reflectors sights are considerably more complex. The collimator in a real sight is not acing directly on the reticle, it is "seeing" an image of the reticle created by a second lens group. The role of the second lens group is to adjust the magification of the reticle so that the image seen by the collimator and subsequently displayed to the pilot is the right diameter to be of use as a range estimate for aircraft of various wingspans at differing ranges.

Tully__
09-04-2006, 02:58 AM
Because the light is divergent it has a FINITE focal range (see diagram) thats why its labelled "Finite distance setting."
This means there is a very limited focal range just as in the middle "Finite distance setting - real image"

The reason is the inverse to the real image (middle senario).


If the image were real it would have to be either between the lens and the sight glass or aft of the sight glass. The reticle image in a reflector sight is forward of the sight glass.

When that sight refers to finite distance, it means less than infinite, not "short". The actual location is directly related to where the reticle is located within the sight in relation to the focal plane. The closer it is to the focal plane, the further away the image appears.

When a collimator lens acts on a light source at its focal plane to make the light parallel, we are talking about a point source! The reticle is not a point source. If the reticle were at the focal plane, light from a single point on the reticle would be parallel after passing through the collimator but light from one point would not be parallel to light from a different point.

By the way, light from every object we see is divergent. If light being divergent prevented us from seeing objects the world around us would be completely invisible.

I'm afraid that the author of the article you've referenced does not fully understand the optical theory himself or has made an over-simplification to try to make understanding of the principles easier for his readers. As mentioned by me on several occasions already, the reticle must be placed very close to but just less than the focal length of the collimator lens behind the lens for the reflector sight to work. The closer you can get to the focal plane the further away the image appears, but at the same time the reticle must be made smaller to appear at a useful size in its projection forward of the aircraft. Again the secondary lens group used for scale and range adjustments can help here, but if at any time the "object" being projected from within the sight is located exactly at the focal plane of the collimator lens, the projected image becomes infintely large and no longer useful as an aiming reticle.

Charos
09-05-2006, 01:38 AM
Originally posted by Tully__:
If the reticle were placed at the focal plane it would appear infinitely large to the viewer. As we know for normal adjustment ranges it appears to have a ring about the same diameter as the wingspan of a fighter plane at 100-200m (depending on sight setting) and this is clearly NOT infinitely large it must not be at the focal plane (though as the magnification is very large it must be very close to the focal plane).)

I agree with you providing the following:

#1 The Human eye viewing is infinitely large.
#2 The eye relief is infinitely large.
#3 The light source is infinitely powerful.

Then we will see our infinitely large image, but since this has no practical application its just a mental gymnastics.


Originally posted by Tully__:
Further, as the apparent location of the image is a greater distance from the eye than the lens (never mind that the light has been bent by the mirror, if you took the mirror out of the equation and looked directly into the top of the sight the image would be the same) it is apparant that the image is virtual as it is on the same side of the lens as the object (reticle) so the reticle must be between the focal plane and the lens.



magnification (http://micro.magnet.fsu.edu/primer/java/lenses/simplemagnification/index.html)


You will see on the above link that the Virtual image lies on the same side as the object (Rose/reticle).
The viewed image is Real if viewed at the viewing side focal plane or nearer to the lens - If viewed after the focal point like the eye in the example then the image is flipped and virtual.
To Quote from theabove pages text:

"In cases where the light rays intersect at a focal point, the image is real and can be viewed on a screen, recorded on film, or projected onto the surface of a sensor such as a CCD or CMOS placed in the image plane. When the light rays diverge, but project imaginary extensions that converge to a focal point, the image is virtual and cannot be viewed on a screen or recorded on film"


Originally posted by Tully__:
You misinterpreted the "light rays" drawn in light path diagrams.
I chose the scale I did so I could get all the lines in without making it too confusing, if I were to put all the objects at scale sizes and distances a PC screen doesn't have enough resolution to show what's happening at the reticle or the eye.


I understand that.



Originally posted by Tully__:
In a practical example if the image were at 200m range with 10m diameter and the reticle were 100mm behind the collimating lens the actual reticle diameter in the simple optical arrangement I've shown would have to be:

100mm/200000mm x 10m = 5mm

As the reticle image in the diagram is only about 60 pixels high, the reticle in the sight in the diagram would have to be less than one pixel (0.03 pixels to be exact) to be in scale. Edit: as an aside, using these figures the focal length would be approximately 100.05mm, so the reticle is VERY close to the focal plane.

You failed to specify where you placed the reticle other than "100mm behind the collimating lens" without specifying where in relation to the focal plane it is.


Originally posted by Tully__:
Real reflectors sights are considerably more complex. The collimator in a real sight is not acing directly on the reticle, it is "seeing" an image of the reticle created by a second lens group. The role of the second lens group is to adjust the magification of the reticle so that the image seen by the collimator and subsequently displayed to the pilot is the right diameter to be of use as a range estimate for aircraft of various wingspans at differing ranges.

That is the job of lens labelled #15 in the following picture.
The Reticle is able to stay at the fixed focal plane of the collimator yet will increase/decrease in size as #15 lens moves toward or away from the mirror.

http://mezek.valka.cz/texty/letadla/revi16b/revi16b2.jpg


Originally posted by Tully__:
If the image were real it would have to be either between the lens and the sight glass or aft of the sight glass. The reticle image in a reflector sight is forward of the sight glass.


I will crop quote the above quote again.

"In cases where the light rays intersect at a focal point, the image is real and can be viewed on a screen, recorded on film, or projected onto the surface of a sensor such as a CCD or CMOS placed in the image plane. When the light rays diverge, but project imaginary extensions that converge to a focal point, the image is virtual"



Originally posted by Tully__:
When that sight refers to finite distance, it means less than infinite, not "short". The actual location is directly related to where the reticle is located within the sight in relation to the focal plane. The closer it is to the focal plane, the further away the image appears.

I agree, short is relative term though. "Long" is as finite as "short".


Originally posted by Tully__:
When a collimator lens acts on a light source at its focal plane to make the light parallel, we are talking about a point source! The reticle is not a point source. If the reticle were at the focal plane, light from a single point on the reticle would be parallel after passing through the collimator but light from one point would not be parallel to light from a different point.


Take a look at the link to the Wiki Lens article you provided earlier.
Go down to the BICONCAVE lens. This type of Lens is the first that our parallel reticle illuminated ring is directed towards (after the mirror).
You can see in the Wiki article a similar thing with 3 parallel light beams directed toward the BICONCAVE lens (Not unlike our reticle situation).
I will quote from the article:

"If the lens is biconcave or plano-concave, a collimated beam of light passing through the lens is diverged (spread); the lens is thus called a negative or diverging lens. The beam after passing through the lens appears to be emanating from a particular point on the axis in front of the lens; the distance from this point to the lens is also known as the focal length

The focal point is virtual not real.



Originally posted by Tully__:
By the way, light from every object we see is divergent. If light being divergent prevented us from seeing objects the world around us would be completely invisible.

In a limited sense your right, Light is reflected and refracted at an infinite number of angles in 3D space around the object in view.
Our eye's are only able to see what light is intercepted.

Nature does have a completely invisible object - The affect is created by a Gravity lens which performs a similar task to an optical lens, the object in qustion is a black hole.

Charos
09-05-2006, 02:32 AM
Originally posted by Tully__:

I'm afraid that the author of the article you've referenced does not fully understand the optical theory himself or has made an over-simplification to try to make understanding of the principles easier for his readers.

That article is directly from:

NAVAL ORDNANCE AND GUNNERY
VOLUME 2 FIRE CONTROL
Prepaired by the Department of Ordnance and Gunnery
United States Naval Academy Edited and produced by the
Bureau of Naval Personnel
NavPers 10798-A
For sale by the Superintendent of Documents, U. S. Government Printing Office
Washington 25, D. C. Price $2.75
1958 edition revised from the 1950 edition


The new material in this publication, and the revision of the book as a whole, were accomplished by officers attached to the Department of Ordnance and Gunnery, U. S. Naval Academy, and by representatives of the departments of Naval Science of four selected NROTC universities, working in conjunction with the Training Division, Bureau of Naval Personnel, and the U. S. Navy Training Publications Center, Washington, D. C.

Tully__
09-05-2006, 03:05 AM
Originally posted by Charos:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Tully__:

I'm afraid that the author of the article you've referenced does not fully understand the optical theory himself or has made an over-simplification to try to make understanding of the principles easier for his readers.

That article is directly from:

NAVAL ORDNANCE AND GUNNERY
VOLUME 2 FIRE CONTROL
Prepaired by the Department of Ordnance and Gunnery
United States Naval Academy Edited and produced by the
Bureau of Naval Personnel
NavPers 10798-A
For sale by the Superintendent of Documents, U. S. Government Printing Office
Washington 25, D. C. Price $2.75
1958 edition revised from the 1950 edition


The new material in this publication, and the revision of the book as a whole, were accomplished by officers attached to the Department of Ordnance and Gunnery, U. S. Naval Academy, and by representatives of the departments of Naval Science of four selected NROTC universities, working in conjunction with the Training Division, Bureau of Naval Personnel, and the U. S. Navy Training Publications Center, Washington, D. C. </div></BLOCKQUOTE>

It's still wrong. http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

Tully__
09-05-2006, 03:19 AM
From the same website on magnification:


When the light rays diverge, but project imaginary extensions that converge to a focal point, the image is virtual and cannot be viewed on a screen or recorded on film. In order to be visualized, a real image must be formed on the retina of the eye. When viewing specimens through the eyepieces of a microscope, a real image is formed on the retina, but it is actually perceived by the observer as a virtual image located approximately 10 inches (25 centimeters) in front of the eye.

It doesn't matter that the light rays are divergent when they reach the eye, the lens within the eye (or camera) is (effectively) bi-convex and refracts the divergent beams so that they converge on the retina to form a real image. The image still appears to be virtual to the viewer as it appears to be further away than the collimator/magnifying glass/microscope and light emerging from the collimator/magnifying glass/microscope is divergent.

Incidentally a magnifying glass can be used to create real images by moving the subject further away from the magnifying glass than its focal length. Magnifying glasses I've played with are typically built such that focal length is somewhere between 20cm and 100cm IIRC. Look at an scene outdoors through a magnifying glass and you'll see that it appears very close and inverted (you'll need to hold the glass at arms length as the image will be further from the
glass than the focal length, or you can project the image onto a piece of paper or something else flat and light coloured).
Using a magnifying glass as a fire starter is also creating a real image... of the sun.

Tully__
09-05-2006, 03:58 AM
Originally posted by Charos:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Tully__:
If the reticle were placed at the focal plane it would appear infinitely large to the viewer. As we know for normal adjustment ranges it appears to have a ring about the same diameter as the wingspan of a fighter plane at 100-200m (depending on sight setting) and this is clearly NOT infinitely large it must not be at the focal plane (though as the magnification is very large it must be very close to the focal plane).)

I agree with you providing the following:

#1 The Human eye viewing is infinitely large.
#2 The eye relief is infinitely large.
#3 The light source is infinitely powerful.

Then we will see our infinitely large image, but since this has no practical application its just a mental gymnastics. </div></BLOCKQUOTE>
It's not mental gymnastics. If you concede that the image must be infinite in size if the object is placed in the focal plane then you must concede that the object (reticle) is not exactly in the focal plane in a reflector sight because the image is clearly not infinite in size. Eye relief has nothing to do with where the image appears, that is dictated entirely by the light paths resulting after the light passes through the lens. Similarly the size of the eye/camera viewing the image is irrelevant, the image location is determined by tracing back the light paths of the light after it's passed through the lens. Yes we'd need an infinitely powerful light source to create an infinitely large image, but that's irrelevant as the image is clearly not infinitely large


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Tully__:
Further, as the apparent location of the image is a greater distance from the eye than the lens (never mind that the light has been bent by the mirror, if you took the mirror out of the equation and looked directly into the top of the sight the image would be the same) it is apparant that the image is virtual as it is on the same side of the lens as the object (reticle) so the reticle must be between the focal plane and the lens.



magnification (http://micro.magnet.fsu.edu/primer/java/lenses/simplemagnification/index.html)


You will see on the above link that the Virtual image lies on the same side as the object (Rose/reticle).
The viewed image is Real if viewed at the viewing side focal plane or nearer to the lens - If viewed after the focal point like the eye in the example then the image is flipped and virtual.
To Quote from theabove pages text:

"In cases where the light rays intersect at a focal point, the image is real and can be viewed on a screen, recorded on film, or projected onto the surface of a sensor such as a CCD or CMOS placed in the image plane. When the light rays diverge, but project imaginary extensions that converge to a focal point, the image is virtual and cannot be viewed on a screen or recorded on film" </div></BLOCKQUOTE>
That's site is correct. Your interpretation isn't. Go back to the wiki article I linked and see how object location is related to image location. If the object is at any distance from the lens greater than the focal length, the image will be real, inverted, on the opposite side of the lens to the object and at a distance from the lens greater than the focal length. If the object is at any distance from the lens less than the focal length the image will be upright, same side of the lens as the object and for object distances greater than 0.5f the image will be further from the lens than f, for objects distances less than 0.5f the image will be closer to the lens than f, and as the object approaches zero distance from the lens so will the image.


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Tully__:
You misinterpreted the "light rays" drawn in light path diagrams.
I chose the scale I did so I could get all the lines in without making it too confusing, if I were to put all the objects at scale sizes and distances a PC screen doesn't have enough resolution to show what's happening at the reticle or the eye.


I understand that.



Originally posted by Tully__:
In a practical example if the image were at 200m range with 10m diameter and the reticle were 100mm behind the collimating lens the actual reticle diameter in the simple optical arrangement I've shown would have to be:

100mm/200000mm x 10m = 5mm

As the reticle image in the diagram is only about 60 pixels high, the reticle in the sight in the diagram would have to be less than one pixel (0.03 pixels to be exact) to be in scale. Edit: as an aside, using these figures the focal length would be approximately 100.05mm, so the reticle is VERY close to the focal plane.

You failed to specify where you placed the reticle other than "100mm behind the collimating lens" without specifying where in relation to the focal plane it is. </div></BLOCKQUOTE> Well if it were at a distance from the lens just greater than the focal length the image would be nearly 200m behind the pilot's head...


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Tully__:
Real reflectors sights are considerably more complex. The collimator in a real sight is not acing directly on the reticle, it is "seeing" an image of the reticle created by a second lens group. The role of the second lens group is to adjust the magification of the reticle so that the image seen by the collimator and subsequently displayed to the pilot is the right diameter to be of use as a range estimate for aircraft of various wingspans at differing ranges.

That is the job of lens labelled #15 in the following picture.
The Reticle is able to stay at the fixed focal plane of the collimator yet will increase/decrease in size as #15 lens moves toward or away from the mirror.

http://mezek.valka.cz/texty/letadla/revi16b/revi16b2.jpg


Originally posted by Tully__:
If the image were real it would have to be either between the lens and the sight glass or aft of the sight glass. The reticle image in a reflector sight is forward of the sight glass.


I will crop quote the above quote again.

"In cases where the light rays intersect at a focal point, the image is real and can be viewed on a screen, recorded on film, or projected onto the surface of a sensor such as a CCD or CMOS placed in the image plane. When the light rays diverge, but project imaginary extensions that converge to a focal point, the image is virtual"



Originally posted by Tully__:
When that sight refers to finite distance, it means less than infinite, not "short". The actual location is directly related to where the reticle is located within the sight in relation to the focal plane. The closer it is to the focal plane, the further away the image appears.

I agree, short is relative term though. "Long" is as finite as "short".


Originally posted by Tully__:
When a collimator lens acts on a light source at its focal plane to make the light parallel, we are talking about a point source! The reticle is not a point source. If the reticle were at the focal plane, light from a single point on the reticle would be parallel after passing through the collimator but light from one point would not be parallel to light from a different point.


Take a look at the link to the Wiki Lens article you provided earlier.
Go down to the BICONCAVE lens. This type of Lens is the first that our parallel reticle illuminated ring is directed towards (after the mirror).
You can see in the Wiki article a similar thing with 3 parallel light beams directed toward the BICONCAVE lens (Not unlike our reticle situation).
I will quote from the article:

"If the lens is biconcave or plano-concave, a collimated beam of light passing through the lens is diverged (spread); the lens is thus called a negative or diverging lens. The beam after passing through the lens appears to be emanating from a particular point on the axis in front of the lens; the distance from this point to the lens is also known as the focal length

The focal point is virtual not real. </div></BLOCKQUOTE>
For that part of the complex lens that makes up the collimator in the sight you've provided a diagram for. If you scroll down that same wiki article you'll see in the section on chromatic abberration (http://en.wikipedia.org/wiki/Lens_%28optics%29#Chromatic_aberration) that multiple lens components can be assembled to for an effective single lens using different materials in each component to cancel out unwanted properties found in each individual component. Again referring to your diagram, the collimator lens is composed of the three components labelled number 5 in the diagram which when combined act as a biconvex lens with no (or very little) chromatic or spherical aberration. The focal point is real but the image is still virtual.



Nature does have a completely invisible object - The affect is created by a Gravity lens which performs a similar task to an optical lens, the object in qustion is a black hole. Indeed, however if divergent light caused objects to be invisible, nature would be completely lacking in visible objects...

Charos
09-05-2006, 04:08 AM
Originally posted by Tully__:
From the same website on magnification:


It doesn't matter that the light rays are divergent when they reach the eye, the lens within the eye (or camera) is (effectively) bi-convex and refracts the divergent beams so that they converge on the retina to form a real image. The image still appears to be virtual to the view as it appears to be further away than the collimator/magnifying glass/microscope and light emerging from the collimator/magnifying glass/microscope is divergent.


The reason why it doesnt matter on a Telescope or microscope is because there is another set of lenses called the eypiece or the ocular lenses that are placed close to the objective focal length. This lens/lenses take the divergent light and merge them again towards a a secondary focal point. the main reason fore that is magnification.


Magnification (or power)=Telescope focal length (mm)
__________________________
Eyepiece focal length (mm)

As mentioned

#1 The system does not magnify the target image.

This means the system does not utilise secodary lenses for that purpose IE: there are no Ocular lenses on the gunsight.



Originally posted by Tully__:
Incidentally a magnifying glass can be used to create real images by moving the subject further away from the magnifying glass than its focal length. Magnifying glasses I've played with are typically built such that focal length is somewhere between 20cm and 100cm IIRC. Look at an scene outdoors through a magnifying glass and you'll see that it appears very close and inverted (you'll need to hold the glass at arms length as the image will be further from the
glass than the focal length, or you can project the image onto a piece of paper or something else flat and light coloured).
Using a magnifying glass as a fire starter is also creating a real image... of the sun.



Ok try this with the magnifying glass.

Grab a piece of paper with Text or similar.

#1 View the text through the glass until it is focused.

#2 Start moveing your eye away from the magnifying glass while leaving it at the exact distance as before.

Beyond the near side focal point the light will diverge.

Tully__
09-05-2006, 04:21 AM
Originally posted by Charos:
Ok try this with the magnifying glass.

Grab a piece of paper with Text or similar.

#1 View the text through the glass until it is focused.

#2 Start moveing your eye away from the magnifying glass while leaving it at the exact distance as before.

Beyond the near side focal point the light will diverge.
If I understand you correctly you want me to set up a maginfying glass so that it is fixed in relation to some text then leaving the magnifying glass where it is in relation to the text, move back from the glass?
Done it, have you? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

All that happens is at some point the image goes out of focus because my eyes aren't able to see the distance to the text (unless I'm wearing my glasses) as I'm short sighted. Text stays in the same apparent location behind the glass.

If you mean keep the glass stationary with respect to my eyes and move the glass & myself back from the text, done that too. At the point where the text approaches the focal length of the glass the magnification causes the image to be too large to see clearly then as the text passes through the focal length sufficiently far that the image is closer to the lens than my head I recover visibility of the text but inverted and apparently closer to me than the glass is. I've done that too. All as predicted by the equation:

1/f = 1/S1 + 1/S2

that the Wiki site shows where f is focal length, S1 is object distance and S2 is image distance.

Charos
09-05-2006, 06:41 AM
Ok Tully we may be getting close now.

But before we Celebrate - it looks like we were BOTH wrong. http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

With the folowing picture in mind .
http://www.mildex.com/images/testequip/optitest/otest01.gif


Now time to whip out the trusty magnifying glass.

Firstly you will need :

#1 Blank sheet of paper with the number "4" in the middle.

#2 a dozen or so books.

#3 magnifying glass.

Hey everyone can join in, this is science in action (we may even be able to build a whole WW2 fighter in a hundred years if we keep this pace up.) http://forums.ubi.com/images/smilies/winky.gif


Now this may take a little while till you get the hang of as it depends on the focal length of the magnifying glass you have.


Firstly and easiest is to place the magnifier on the stacked books so that.

#1 The number "4" is BEYOND the focal length of the magnifying glass (henceforth known as MG)

This is representitive of our middle diagram.

Observations:

- At small eye relief the image is blurred.
- As you move your eye away the image snaps into focus magnified BUT
its now inverted and moves the opposite direction to your head.

NB: This is what I mentioned would happen a few pages ago.

-Also at high Eye relief due to the divergent light paths you will notice
a secondary image appear - each eye is now seeing a seperate image.
Close one eye and its associated image dissapears.

________________

#2 The number "4" is CLOSER than the focal length of the MG.(lower diagram)

Observations:

- At small eye relief the image is in focus.

- As you move your eye away the image stays in focus but magnifies further.


__________________


#3 The number "4" at focal length of MG. (Upper diagram)

- At small eye relief image is in focus.

- As you move your eye away image stays in focus and gets large quickly to the point where at large eye relief it starts to distort.


____________________



So to sum up the Winner is the lower scenario with the divergent light paths.


IE: Not divergent after a focal length crossover - divergent the whole light path.

Charos
09-05-2006, 05:56 PM
Originally posted by Charos:
Ok Tully we may be getting close now.

But before we Celebrate - it looks like we were BOTH wrong. http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

With the folowing picture in mind .
http://www.mildex.com/images/testequip/optitest/otest01.gif


Now time to whip out the trusty magnifying glass.

Firstly you will need :

#1 Blank sheet of paper with the number "4" in the middle.

#2 a dozen or so books.

#3 magnifying glass.

Hey everyone can join in, this is science in action (we may even be able to build a whole WW2 fighter in a hundred years if we keep this pace up.) http://forums.ubi.com/images/smilies/winky.gif


Now this may take a little while till you get the hang of as it depends on the focal length of the magnifying glass you have.


Firstly and easiest is to place the magnifier on the stacked books so that.

#1 The number "4" is BEYOND the focal length of the magnifying glass (henceforth known as MG)

This is representitive of our middle diagram.

Observations:

- At small eye relief the image is blurred.
- As you move your eye away the image snaps into focus magnified BUT
its now inverted and moves the opposite direction to your head.

NB: This is what I mentioned would happen a few pages ago.

-Also at high Eye relief due to the divergent light paths you will notice
a secondary image appear - each eye is now seeing a seperate image.
Close one eye and its associated image dissapears.

________________

#2 The number "4" is CLOSER than the focal length of the MG.(lower diagram)

Observations:

- At small eye relief the image is in focus.

- As you move your eye away the image stays in focus but magnifies further.


__________________


#3 The number "4" at focal length of MG. (Upper diagram)

- At small eye relief image is in focus.

- As you move your eye away image stays in focus and gets large quickly to the point where at large eye relief it starts to distort.


____________________



So to sum up the Winner is the lower scenario with the divergent light paths.


IE: Not divergent after a focal length crossover - divergent the whole light path towards viewer.