Has anyone handheld--let alone used--a camera with a bulk film back? Can it technically be done? I'd want to use it for PJ/wedding type work. Here is why: I want to shoot Kodak Vision3 500T film. The problem is, the labs that develop it only do so in longish lengths for motion picture users. I think a 250 exposure back for a Nikon F4 would hold enough that some lab would process it for a reasonable fee. I'm guessing it would be quite unwieldy at first...and I'd have to really start working out, seriously...but it may be worth it.