At this time I know of only two underwater housings for current medium format cameras, Hasselblad and PhaseOne. We will be hosting an underwater workshop August 14 to 19, 2011 in Boca Raton, Florida for fashion/fine art/centerfold photography using the hasselblad systems.
Hasselblad Underwater Fashion Workshop
I was a Pentax 6 X 7 and 645 shooter for years and I still own 645 AF glass and film bodies. Since U/W photography is my passion I would of course love to see a quality housing made for the 645D. Being more of a field camera than a studio camera I feel it would be idel for MF U/W photography. Most U/W work is done with macro and very wide lenses. The 120 macro would be well suited to this task and I would love to get the new D FA 645 25 mmF/4 behind a quality optical glass dome port.
Having used both the Hasselblad and Phase systems underwater I would love to see another player.
Phil Rudin