Taking pic of prop -- graphical calc

Fastglas

Fastglas

Pre-takeoff checklist
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Thought this was pretty interesting. Came up in my news feed this morning.

Petapixel.com:
"If you’ve ever photographed spinning airplane propeller or helicopter rotor blades with your smartphone, you may have found that the spinning blades were turned into bizarre shapes in the resulting photo. What you’re seeing is distortion caused by a rolling shutter, when a CMOS sensor captures a scene by scanning across it very quickly rather than capturing the entire frame at once."

Calculator here:
https://www.desmos.com/calculator/
 
This isn't just a digital camera issue. Cameras with focal plane shutters often experience motion artifacts as the curtain moves across the film plane. Slower "shutter" speeds decrease that issue. This is why you can lessen the problem by putting a neutral density (gray) filter over the lens to force the slower speed.
 
flyingron said:
This isn't just a digital camera issue. Cameras with focal plane shutters often experience motion artifacts as the curtain moves across the film plane. Slower "shutter" speeds decrease that issue. This is why you can lessen the problem by putting a neutral density (gray) filter over the lens to force the slower speed.
Click to expand...

Yeah, if you look at old racing pictures from the teens and twenties, it looks like the wheels are forward leaning and oblong.
 
Yeah, as said this is an issue with nearly all cameras, analog or digital since it's hard to capture an exact moment it time. Instead it's a very fast electronic or digital scan of a small window of time. For the real high speed photography (bullets passing though playing cards stuff) they work around this issue by leaving the shutter open and instead supplying a very short pulse of light as the flash.
 
Ray Harroun drove the winning car in the first Indianapolis 500:

HarrounRaywinning72.jpg
 
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