1080p from DSLR such as Canon vs. HD video cam solution

I was wondering whether someone with video experience could let me know whether they feel that a new Canon T2i or 7D can accomplish great underwater video (including close ups) as decently as a true HD video camcorder. I have heard that the Canon cameras cannot autofocus during video mode and that they recommend that everything be at least 2 feet away from the camera. Is it still possible to get great closeups with great focus from one of these DSLR's or must one go to a seperate video solution?

Thank you,

David

The resolution will not be nearly as good as a pro camcorder, squeezing out 600 lpi with plenty of aliasing. However, the ISO noise is very low and you can have a full fisheye lens and extra wide lenses, as well as ability to use macro lenses like the 100mm and 180mm which do 1:1. It's also easier to get greater than 1:1 with extension tubes and TCs.

Ergonomically, a DSLR housing makes it more difficult to shoot super macro because it's not well balanced as a video housing. WB is more of a pain to get on a ViDSLR. AF works but not during recording. Most housings cannot use the zoom AND focus for wide zooms.

Overall ViDSLRs are harder to use for video only. It's a great tool to be able to shoot both on tap. Resolutionwise, it's better at closeup than wide angle, as the resolution limits detail so filling the frame with a subject is better. However, that's subjective and depends on what you want to do with it.