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b2spirita
10-06-2007, 01:59 PM
What are your personal faves for in cockpit gunsights? I like the types found on spits and hurricanes as they allow for a much better view. Opinions??

Taylortony
10-06-2007, 02:05 PM
I like the FW ones.. you know shift F1 i think repositions the view to the centre?

ImMoreBetter
10-06-2007, 02:06 PM
The 190 bar.

Friendly_flyer
10-06-2007, 02:24 PM
The sight in the Finnish Brewster is nice, apart from that I prefer the Spit/Hurri-sights.

Divine-Wind
10-06-2007, 02:35 PM
I rather like the one in the IAR-80. Just something about the early sights that catches my eye.

Besides that the Spitfire's, and the Warhawk's. Not sure why I like the latter's, I just do...

general_kalle
10-06-2007, 02:40 PM
P51 Gyro sight.

Stew278
10-06-2007, 02:43 PM
The K-14 sight on the P-51D is nice.

The telescopic sight on the Ki43 is good because you can aim real well with it. But the limited view leads to target fixation.

The MC.200 series also have cool gunsights.

Wild.Bill.Kelso
10-06-2007, 03:52 PM
What are the ones with the angled piece of glass, and how did that work? I saw one at the Mustangs & Legends Airshow last week, and told my brother they are a kind of WW2 HUD, because in IL2 we see the gunsight designator in them. But I don't have a clue how they worked...

Divine-Wind
10-06-2007, 06:27 PM
Deflector sights? They worked with mirrors, that's all I know.

mortoma
10-06-2007, 09:31 PM
All sights in all planes are good when you have an enemy aircraft in them.

ImMoreBetter
10-06-2007, 11:28 PM
I might be able to dig up something on the reflector gunsights.

Gimme' a few moments to stop being lazy. Then I'll start looking for it.

Edit:
http://www.ww2aircraft.net/forum/attachments/other-electrical-systems-tech/48039d1190404379-reflector-gun-sight-reflector-sight.jpg

Page 7. (http://www.gbairspares.co.uk/reference/ap112e-ggs-mk5.pdf)


Also:
N-2 and N-3 gunsight manual (http://www.mediafire.com/?ezclwtxu2yg). Not sure what it says, just thought it was worth bringing up.

b2spirita
10-07-2007, 09:09 AM
i thought that ths would be a big discussion - given how vital the sights are and the shift +f1 joke

Wild.Bill.Kelso
10-07-2007, 12:10 PM
Did you want the Shift-F1 to display something different? Another cockpit view?

DKoor
10-07-2007, 12:19 PM
P-38 has the best gunsite.
Fakt.

Lurch1962
10-09-2007, 09:18 PM
Wild.Bill.Kelso,
I'll try to be brief. A WWII era gun sight is an extremely simple affair. There are 4 main components, which I'll list in the order in which light travels through the device on the way toward your eye:

1) Lamp. Obviously, it provides the light for the image of the reticle you see.

2) Reticle. A pattern of cut-out lines/circles in an opaque material (sometimes sheet metal).

3) Collimator--the heart of the system. This is a convex lens, which in the simplest terms "focuses" the image of the reticle pattern. More precisely, the lens collimates the emergent image, making the otherwise divergent light bundles which comprise each point in the image parallel. This has the effect of making the reticle pattern appear to lie at infinity, instead of the actual distance it lies from your eye (~2 feet or so).

4) Reflector plate. A flat plate of glass, angled at 45 degrees. The upward directed image of the reticle through the collimator is redirected by reflection through 90 degrees, so as to be in line with the plane's guns. The reticle pattern IS NOT PROJECTED ONTO THE REFLECTOR. You are seeing the reticle THROUGH the reflector, lying at an infinitely large distance out in front of your plane. This is why when your head moves, the reticle pattern appears to "slide" around against the very nearby reflector. Moreover, in LW planes, with the sight displaced to the right, your virtual pilot must have his head similarly displaced (SHIFT-F1) in order to more properly alighn his eye.

=============================

The ultimate purpose of an optical sight is to eliminate parallax error.

The old-fashioned ring and bead sight uses two separate pieces so as to eliminate parallax error. But the disadvantage is that the pilot his to exactly align his eye on a fixed sight line, or axis, in a sometimes bouncing cockpit.

The optical sight allows some freedom of movement of the eye while maintaining the sight picture. You can see, then, that a larger collimator lens/reflector plate combo would further relax the constraints on exact alignment.

In the game, for pretty much all gun sights you can see the collimator represented as a curved lens "in profile", just under the reflector plate. And for many of them, the reticle pattern is actually larger than the collimator. This is unrealistic--the reticle can never appear larger in size than the collimating lens. (But that's a minor quibble. IL-2's gun sights are light years better than those in CFS, which show what amounts to a reticle "painted" onto the reflector!! YUK!!)

The modern amateur astronomer has at his disposal what is in effect a WWII-style gun sight with which to aim his telescope. They're called "unit magnification finders," which project a bullseye "onto" the plane of the sky. Search "Telrad" or "Rigel Quik Finder" for two examples.

Wild.Bill.Kelso
10-10-2007, 07:12 AM
You are seeing the reticle THROUGH the reflector, lying at an infinitely large distance out in front of your plane. So, does this appear kind of like a optical illusion? Like when you look at a holograph and it appears in the distance behind the actual picture your looking at?

Thanks for the info.

PBNA-Boosher
10-10-2007, 08:26 AM
Personally my favorite gunsight is the one in the MC.202 Series III and G.50, although I'm not such a fan of the Breda Safat MG's. I also reallly like the Yak's gunsight and the sight in the P-40 and 38. I like their guns a bit more though. The Browning M2 and UBS seem more accurate than the Safats and the Hispano and ShVAK in the Yak and P-38 give more hitting power, although the six .50's in the P-40 aren't anything to laugh at either.

Divine-Wind
10-10-2007, 09:11 AM
Thanks for the explanation, Lurch!

Rood-Zwart
10-10-2007, 09:43 AM
I like the 2nd gunsight on the mc 205 best

MPHagen
10-10-2007, 11:51 AM
Here is a photo of an actual navy gunsight taken at the Air and space museum in Washington DC.

http://i24.photobucket.com/albums/c49/MPHagen/IMG_0066.jpg

Lurch1962
10-10-2007, 05:30 PM
So, does this appear kind of like a optical illusion? Like when you look at a holograph and it appears in the distance behind the actual picture your looking at?

No illusion at all. It's basic optics. You can think of it this way... The collimator is in effect a camera lens designed to sharply focus an image for an object lying at infinity. But now you're looking into the "camera" through the lens, so that you can see the "film" image itself. If you took a photo of the reticle pattern, you would have to focus your camera lens for infinity for sharpest focus.

Look at the image MPHagen posted (Thanks!!). What's the sharpest element in the photo? You got it... the reticle pattern! Its image lies at infinity, while the gun sight and printed material just behind it is blurry. (Actually, it sure looks like the camera shook a little during the exposure, as there appears to be lateral motion-induced blur.)

I'd be curious to know how the "background" plane was rendered in the display. It does give the appearance of appearing through some kind of "window", and possibly even having a collimating optic so as to render it reasonably sharp. At least, that's how I'd do it. Otherwise the spectator would see the reticle move across the plane's image when their head moved even slightly--that would ruin the effect.

MrMojok
10-10-2007, 05:35 PM
Here:

http://members.cox.net/f1dude/GML2007/DSCF0813.JPG

http://members.cox.net/f1dude/GML2007/DSCF0814.JPG

Lurch1962
10-10-2007, 06:04 PM
Excellent shot, MrMojock!

It shows that the reticle pattern is NOT projected ONTO the reflector plate, else both would have to be seen at the same degree of (de)focus. Note how all nearby things (especially the gun sight housing/reflector) are quite blurry, while the reticle is rather sharply focused, like the more distant background plane and hangar walls. Moreover, see how the poster of the target plane is blurry as well, it not being far enough back to be even close to the focus plane of the reticle.

Another thing to contemplate. If you were to stand ABOVE the gun sight and look down into it, through the reflector plate, you'd see the very same reticle pattern, but it would be rather brighter. This is because the reflector is bouncing only a few percent of the light toward the pilot, and the other 90+% of the light "escapes" upward. (Unless a partially reflecting coating is used--like a beam splitter.)

No matter how close or far you are from the reflector, the angular size of the projected reticle WILL NOT CHANGE. That's another benefit of the collimating lens. Of course, if you move too far back, the now smaller-appearing reflector will not allow all of the reticle to be seen at once--you'd have to move your head around to see all the parts which aren't visible in one go. If the reticle was projected ONTO the reflector, its angular size would change as the pilot moves his head fore/aft, just as it does for the reflector itself.

Actually, the only way to project a pattern ONTO a surface is to have that surface roughened or coated with an appropriate scattering substance, like a movie screen. You can't effectively project ONTO clear glass.

Another observation on MrMojok's image... The lamp is either not centered properly, or is tilted off-axis. Note the strong difference in reticle brightness across its diameter.

Divine-Wind
10-10-2007, 07:53 PM
I wonder how it would look if everything you saw were focused at infinity?



Someone go find raaaid!

Lurch1962
10-10-2007, 10:17 PM
To all intents and purposes, anything beyond about 200m (about the limit of 3-D perception) can be considered to lie at infinity. Cameras all have an infinity focus position. An object can be said to be at infinity when the light from it arrives at the observer in a flat wavefront (parallel light rays is another way to think of it.)