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Bravo! Bravo! (bruce)


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Greetings all,


Ok, not sure if anyone has had this "distortion" before, and I would ask you to figure it out, however, when I asked my A&P for advice, he said to add viagra to the fuel tank. Not much help.


Well, I took this picture with the engine running, with an Iphone. That's what I got. It continuously does this. Why wouldn't the blades both be drooping/rotating in the same direction? those are the questions I don't have an answer to.


Glad this isn't what my prop really looks like.


Anyone else with this result from an Iphone? Any ideas why it happens?091_help.gif.c9d9d46309e7eda87084010b3a256229.gif




Bruce (up and over)





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Guest Maj Millard

Have had the same results with my LG phone both from within the cockpit and also from out side. Have some great shots of Cessna Caravan props during ground run ups, almost an art form and I'm wondering what I can do with them, they actually separate from the hub and do their own thing out in space. 024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif



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Hey Slartibartfast, the N rego and the hangars in the background, that's not at Schellville CA is it ?.

Well, I may be barking up the wrong tree, but considering this was posted in the "Laughter" forum, I figured he was being facetious and replied in kind.


I googled a photo of the same aeroplane and said it came from my non-existant iPhone and had no prop droop.


As if I would go 4 years backward in technology and buy an iPhone 040_nerd.gif.a6a4f823734c8b20ed33654968aaa347.gif


The caption said it was Santa Paula.



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First thoughts.


Gees it must be hot there!!


Hangon, Its one of those Australian prop that automatically takes you home if your lost.


The only logical answer that I can think of is the rate at which the photo is converted from light to digital information.


It would seem that this conversion would happen from the right to the left of the photo.


If you picture the prop spinning in an anti clockwise direction (viewed from the front)at say 1000 rpm and the scan is from right to left, the scan rate for the distance of the prop circle (or oval) could be estimated by drawing a line from the tip of the prop on the right through the hub and measuring the angle between the extended line and the tip on the left side of the photo.


If the angle is say 90 degrees between the extended line and the tip on the left (not taking into account the variations due to the angle the photo was taken from) then you would say the scan rate through this part of the photo (from right to left) took .25 revs at 16.66 rps meaning the scan took 15 milliseconds to convert the prop from light to digital image working from right to left. (about 60 milliseconds for the whole photo)


I don’t think its due to capture speed of each pixel or the prop would be blurred.


Heres an experiment to see if the assumptions are correct


Take a photo from the rear of the plane catching the prop in a horizontal position and the prop should look bent up on both sides


Take a photo from the front (straight on) catching the prop in a vertical position and it should look relatively normal


P.S this is just a guess but the only thing that makes sense to me. I don’t know how digital cameras work when transferring data.


P.P.S It’s late. Don’t be surprised if my calculations are totally wrong.036_faint.gif.544c913aae3989c0f13fd9d3b82e4e2c.gif



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