ELI5- why do screens/lights flicker in videos taken by phone or even yt vids, but not in movies and professional productions?

Question

ELI5- why do screens/lights flicker in videos taken by phone or even yt vids, but not in movies and professional productions?

In: 674

Answer 1

Shutter speed of the camera vs refresh speed of the screen. Your camera doesn’t take an image instantly. Instead it goes down row by row kinda like a printer. Your monitor does the same thing. When these two speeds line up poorly they cause the flickering. You don’t see this in movies cause they can do tricks like CGIing in the screens later, rotate the camera so the camera is going left to right instead of top to bottom, or you can get cameras that can sync with screen refresh rates to eliminate the flicker.