How do I record a computer monitor without banding/flickering with a Canon t2i/550D? As you've probably guessed, when recording video with a computer monitor in frame I am getting banding. I'm aware that this has to do with refresh rates of the monitor vs the scan rate of the camera or something like that. I've read that most cameras have a feature to adjust for this - synchro scan, clear scan or variable scan is what I've seen it referred to as. However, I can't find anything on what or how to do this with my Canon t2i.

I've seen a number of videos where people do this with a t2i, so I'm sure it's possible, I'm just not sure how to set the camera up properly.

Here is a video using a t2i to record a computer screen without banding.

I've noticed that I can adjust f/stop and shutter speed to get varying results when put in to Tv mode. I'm having trouble getting to a setting that has minimal/no banding and isn't either under or over exposed.
While reviewing the Instruction Manual for the Canon 2Ti EOS 550 on page 127 you will find information on how to manually set the shutter time. Here is the pdf download for the manual:
http://gdlp01.c-wss.com/gds/9/0300003169/01/eosrt2i-eos550d-im-en.pdf

There is wide range of 1/4000 to 1/30 of a second to work with depending on your frame rate.

For 50 fps or 60 fps the range is 1/4000 to 1/60.

For 24, 25, &amp; 30 fps the range is 1/4000 to 1/30.

I suggest that you try different shutter times at your preferred frame rate. I know this is not definitive, as I don't have this camera, nor have I tested this. However, the flicker you are referring to is as you suggest a synchronization issue; you are trying to have the camera capture at a rate that synchronizes with the display. Another thing you can try is change the display frame rate, if you have this option on your monitor.

Hope this helps,