I am using my canon 60D with a Manhattan LCD monitor 89B. The issue is when I am in preview (before I hit the record button), the momitor aspect ratio looks fine. Then when I hit record the monitor stretches the image to look sorta like cinemascope, with everything fat. then when i playback, the image is fine, filling the screen.
I can't seem to find the setting in the 60D to fix this. I plugged my LCD monitor into a nikon d7000 and its recording image aspect ratio is fine. So, I have to assume it is coming from the camera, not a setting in the monitor.
Not familiar with the monitor, but the 60d in video record mode drops HDMI output to 480p, which is SD and a 4:3 aspect ratio. The Nikon is stated at 720p output in video record, or HD and 16:9. If your monitor doesn't have an option for SD/480p format, it will always stretch that signal. I have a T2i (same 480p as 60D), so I haven't invested in a monitor with resolution over that yet (plus they cost as much/more than my camera). Hope this helps...ML