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View Full Version : Here's a challenge: duplicate this effect



SkyChimp
04-09-2004, 06:14 PM
http://www.grunts.net/album/navy/f6ftakeoff.gif

Regards,
http://members.cox.net/us.fighters/wildsig.jpg

SkyChimp
04-09-2004, 06:14 PM
http://www.grunts.net/album/navy/f6ftakeoff.gif

Regards,
http://members.cox.net/us.fighters/wildsig.jpg

DONB3397
04-09-2004, 06:22 PM
Where did you find it? I've seen this before, but can't remember the source. It's hard to believe it was done with standard exposures on black-and-white film, reworked in the darkroom...not 'photoshopped.' These guys were good.

I'm lucky enough to have received from an uncle all of the National Geographic magazines from 1940 to 1945. The war photos are hard to believe, they're so sharp.

http://us.f2.yahoofs.com/bc/3fe77b7e_1812a/bc/Images/Sig---1.jpg?BCMCkdABH1uSLZQo
There is no 'way' of winning;
There is only Winning!

luthier1
04-09-2004, 06:26 PM
What happens if we won't rise up to meet it? http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

http://www.il2center.com/PF.jpg

necrobaron
04-09-2004, 06:48 PM
Can someone explain to me exactly what I'm looking at? I've never seen this "spiral" effect.

"Not all who wander are lost."

Fennec_P
04-09-2004, 06:59 PM
It is just contrails from the propellor blade.

Same phenomena as trails from wingtips. Common with helicopters too, mostly seen in a naval setting (humidity).

http://members.shaw.ca/fennec/flakw.jpg

necrobaron
04-09-2004, 07:01 PM
Ah,I see.http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

Is this a common occurence? What causes it?

"Not all who wander are lost."

Fennec_P
04-09-2004, 07:10 PM
The low pressure air coming from the blade tip can hold less water than surrounding high pressure air, so the water in that air condenses into a visible vapor.

Same with aircraft wing, which has lower pressure on top that on bottom. At high AOA, the pressure on top decreases, and water in that air condenses.

The higher the humidity, the longer it takes for this water vapor to be re-absorbed in the surrounding air. Since the air over the sea is almost always at saturation, the trails will stay longer.

http://members.shaw.ca/fennec/flakw.jpg

LEXX_Luthor
04-09-2004, 07:17 PM
Somebody posted a P~38 pilot memoir and there was told of P~40s used in training. The accepted correct turn to final was judged by wingtip contrails and the dude on the ground would tell P~40 pilots that were not pulling hard enough to make contrails that they have to turn harder. On dry days this resulted in P~40s stalling into the ground. They had to change that method of judgement.

heywooood
04-09-2004, 07:31 PM
Thats a great effect - I've only seen it one other time, quite recently in fact.

Opening night in Dodger stadium.. caused by Phil Nevins bat when he hit that Grand Salami !! Padres win! Padres Win!!! http://ubbxforums.ubi.com/images/smiley/88.gif

JG7_Rall
04-09-2004, 07:46 PM
That's one huge bird....I knew it was big but I didn't think the landing gear was as tall as a person http://ubbxforums.ubi.com/images/smiley/blink.gif

"Son, never ask a man if he is a fighter pilot. If he is, he'll let you know. If he isn't, don't embarrass him."
Badges!? We don't needs no stinkin' badges!

chris455
04-09-2004, 08:08 PM
Photographic anomaly.

http://members.cox.net/miataman1/P47.jpg

Cage50
04-10-2004, 01:05 AM
Wasn't this referred to as a Halo?

Vengeanze
04-10-2004, 01:31 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by JG7_Rall:
That's one huge bird....<HR></BLOCKQUOTE>

No, I think he was refering to Skychimp. http://ubbxforums.ubi.com/images/smiley/16x16_smiley-surprised.gif
And now the chimp will be all annoying for a week cause of that. http://ubbxforums.ubi.com/images/smiley/blink.gif http://ubbxforums.ubi.com/images/smiley/16x16_smiley-wink.gif

/Ven

"Maybe for someone more easy to write something than to make something?"
- Oleg Maddox

EmbarkChief
04-10-2004, 08:58 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by chris455:
Photographic anomaly.

http://members.cox.net/miataman1/P47.jpg <HR></BLOCKQUOTE>

Um, no. Fennec_P hit the nail on the head, I've seen the effect in person with helicopters on humid days.

Aztek_Eagle
04-10-2004, 09:00 AM
here is one from my pictures of airplanes
http://www.angelfire.com/art2/robertosgallery/C1308.JPG

Aztek_Eagle
04-10-2004, 09:03 AM
something is wrong my signature not showing...
http://www.angelfire.com/art2/robertosgallery/CORSAIR7.JPG

DblGonzo
04-10-2004, 10:05 AM
I used to see this almost every day. I spent 5years on the USS Eisenhower. The Helos and the C-1's and E-2's.