Is there any relation between a Exposure & Flicker

Question

I am trying to understand if there is any relation between Exposure(Manual/Auto) function of a Camera and Flicker effect that might be visible in a video shot by that camera?

If one has to do flicker removal, does it have any commonality with the Auto exposure parameters like Exposure time, exposure gain? Can those parameters in anyway tuned/changed to remvoe flicker effect?

Answer 1

Video is refreshed at a certain rate, depending on the display device, between 24 to 60 FPS. Any time you shoot video a a faster shutter-speed you risk the camera taking shots will the between refreshes.

If you take a photo with a slower shutter-speed, say 1/20s, then the camera will capture an entire refresh cycle and the flicker will go away. Use shutter-priority (S or T mode, depending on your camera), Manual (M) or time-aperture (TAv) mode to control shutter-speed yourself.

PS: I realize your question is slightly ambiguous. I am assuming you are taking a photo of something that is playing a video. If you are shooting a video of a video, then your question is off-topic here.

Answer 2

As Itai indicated, there are a couple of possible questions here. CRT (picture tube) video devices paint images on their screens using an electron "gun" that scans left-to-right and top-to-bottom. Photos taken with a fast shutter speed will catch a display like this in mid-paint, showing recently-painted lines brightly, with a darker area just below them (about to be refreshed). Although LCD screens also have a "refresh rate", you don't see the same kind of dimming between pixel painting, so this type of problem is much more subtle (you can still catch a picture in mid-paint, but it's just based on movement in the video). I used to have a Ricoh SLR with a "video" setting designed specifically to keep the shutter slow enough to avoid this effect when shooting a CRT. Quaint, huh?

If, on the other hand, you're talking about the "rolling shutter" video effect seen to some extent on most CMOS DSLR's, we're staying clear of video questions here, but you might have some luck with this on avp.stackexchange.com/.