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effect of Low duty cycle lights on digital imagers.
Posted: Mon Dec 16, 2013 6:05 pm
by hanelyp
Something to consider: The effect of lighting driven at high enough frequency to not be seen as flickering by the human eye (60-100 Hz) with a very low duty cycle, as seen by common digital imagers. My thinking is the digital camera will see striping as different portions of the image see different numbers of flashes between pixel reset and read.
Re: effect of Low duty cycle lights on digital imagers.
Posted: Mon Dec 16, 2013 6:28 pm
by DeltaV
Re: effect of Low duty cycle lights on digital imagers.
Posted: Mon Dec 16, 2013 11:12 pm
by scalziand
This video highlights the strobe effect of some cheap LED lights.
http://www.youtube.com/watch?v=1IDf16R_eJ0
I've also noticed that cars with LED taillights seem to flicker when when recorded by dash cams.
Re: effect of Low duty cycle lights on digital imagers.
Posted: Tue Dec 17, 2013 12:28 am
by hanelyp
LED bulbs flickering is no surprise. The simpler drivers I know of for running LEDs of AC would flicker them at 100-120 Hz, twice line frequency.
What I'm looking at is a flicker fast enough the human eye won't notice, but hard enough to drive a camera bonkers. If filmed at 600Hz, like the video scalziand linked, portions of every 6th to 10th frame would be over exposed, the remaining frames seeing the lamp dark.