When I decided to start shooting video ( about a year and a half ago...) I wanted to approach video with the assumption that I would like it, and that it was something I could take to a high level....this meant I did not want to begin with a low end system, be limited by it, and then end up having to scrap it and start over with a better system.
Many of the SLSR's on the market appeared ideal for me, however, I ended up with the canon 5 d mark II for it's spectacular low light capabilities ( important in many underwater scenarios) and for the lens choices I would have.
I also knew that to get good colors in my videos, I would need powerful lights....I elected to go with Apollo lights from Halcyon...you wear a big cannister ( the battery part) on your waiste, this becomes part of your actual weighting for the dive, and if you breathe through a long hose primary, it is perfect to route the long hose under. The dual light heads of the big appollo produce great light, and allow me to disperse it as much as desired...you still need to be a foot or so away from your primary bacjdrop to ge the rich colors you want--this is true with any lighting system. Good video of a shipwreck, means being right on it--litterally a foot or to away from decks or walls. Same with a reef.
Get 10 feet away and you get blues dominating on all but the shallowest dives, and a general lack of the impressive color we want to capture.
I went with an Aquatica Housing....good to 400 feet, and very rugged ..i.e., unlikely to leak.
I use Vegas Video to edit, and cineform ( NeoHD) to convert the canon format ( h264) to a cineform avi....much bettr to edit with, and the cineform system has a program called First Light that can apply a white balance or color correction instantly to a clip, whether 1 minute long or 1 hour long.....While I run the canon with lights on AWB ( auto white balance) , whenever the colors don't look right, it is instantly fixed in First light.
Here is one of my short compilations:
6 minute Tour version of "Why Divers prefer Palm Beach" video - YouTube ( ps... my friend Jimmy Abernethy shot the aerial with a Go Pro on his Flying Boat)