I recently noticed these three green bars that appear on my footage when recording video on my 7D. At first I thought it would only show up when you set the aperture and shutter speed at extreme settings-- and then it started showing up in some of my shots again (primarily in not-so-great lighting situations... not necessarily low light-- but just plain overhead lights in an office rather than daylight temperature lights). I try to compensate by throwing my ISO way up... but I don't think it should be doing this. Has anyone else had this issue with their 7D or DSLR? I'm trying to figure out if there's something I can do on my own-- or if I need someone to repair it.
I'm not sure but it sound like what you are describing is flickering caused by fluorescent lighting - it could look like bars rolling up and down walls and other parts of the image. There have been several threads here on this forum (with screen shots) providing hints on how to repair footage damaged by fluorescent flickering and how to avoid it in the first place.