I don't do a lot of video and had the studio set to hot lights today for a short bit of video.
Everything looked good on the back of the screen but 2 seconds after the rec button was pressed the video went about 2 stops darker than normal, I could hear the aperture blades closing in.
Phoned Canon but they couldn't advise. Used the 1D4 instead which didn't have this issue.
Any suggestions as to why this is?