Quote Originally Posted by TheFlyingCamera View Post
With 4x5 inch size, it becomes possible to consider roll-film - you can still get rolls of 4" wide b&w film and perhaps color emulsions as well. You'd have to build in some kind of transport mechanism for the film and a way to make it light-tight along with being water-tight. If 8" or 10" (9.5" or whatever it is) roll film is still available, I don't think I'd want to know what the weight of something like a roller transport mechanism for that would be. The motorized back for my RB67 is heavy enough, and it only needs 4 AA batteries!
Yes, I think 9.5" rollfilm would go even further into insanity territory even just from a pure image quality output; not something that'd lend itself to versatility on a dive.
I can (and do) use a 6x17 back on my 5x7 (1x 9V battery there); its only a 120 back (vs 220) and I have to choose: e.g. color or b/w before the dive , but 4 shots is sometimes better than two (I can do 2 shots of 5x7/dive and of course can load different emulsions).