Quote:
Originally Posted by silkstone
I'm not wanting to hijack... 
.... but there's an interesting phenomenon in one of Chris's shots - the first in his link - the chopper blades appear to be curved. Why?
This cropped up somewhere else a while ago, and I did some research with a piece of cardboard and a lathe to find the answer. Any guesses?
Clue: It only happens with (D)SLRs.  |
This kind of thing is usually to do with the focal plane shutter. Since the blades move across the image plane, one following the other, as a narrow slit pats of the image are recorded before other parts and so it something is moving fast enough it will be in a different place at any single time during the movement of the shutter blades causing distortion.
There is a very famous picture by J. Henri Lartique of a racing car (
» Focal Plane Shutter Distortion) showing this effect on the wheels taken with a camera using a very early 'moving blind' type shutter.
Is this is or is it something else you have found?