Making video with Canon 600D

Canon SLRs video performace wrote:

[snip...] The full HD brought the worst performance. Anytime, when the camera is moved horizontally, all the vertival lines of the recorded objects jumps.

Hmm.. This could either be the rolling shutter effect, or the monitor is not refreshing at the same rate as the camera is recording video frames.

Rolling shutter

The image takes a certain amount of time to download from the CMOS chip to the cameras memory. These DSLR cameras have no global electronic shutter. All they can do it start the exposure a line at a time.

Let's assume the shutter speed was set to 1/1000. Each line of the exposure is started at exactly 1/1000 of a second before it is downloaded to the cameras memory. But the complete picture download still takes say 1/60 of a second. This means if there is rapid motion, the image can bend/stretch/shrink depending on the direction of the movement.

Some cameras are faster at downloading the image than others, hence this effect can be very model dependent.

Refresh rate

If the video is recorded at say 25fps and played back at a refresh rate that is not a multiple of the recorded video (e.g. 50/75/100 fps) then horizontal motion will appear to have torn edges and also video may flicker.

The camera can be set to 24, 25 or 30 fps on 1080p. So it is quite flexible here. Check your monitor/graphics card settings if this is the case.

There is software available to reduce this effect, but I have little info of this (can someone else please help here). I always record at 25p (as I am in the UK), my monitor is set to 75Hz and my TV is 50Hz. If I set the monitor refresh to (say) 60Hz - I see this problem.

Hope this helps

Regards

Andy.