Ok so i've wanted to make a pinhole for a while but I wanted to do it the "right way"... It came to me that i could use a junker back that doesn't work on the camera anymore... plus it's 6x7 so that's pretty convenient... So I measured the length to the film plane and it was about 35mm so I used a calculator and calculated I needed about a .24mm aperture to cover the 6x7 area... worked out pretty well... I can use the dark slide as the shutter or i can use a piece of tape up front... plus the back has a counter on it and an advance knob to measure precisely to the next frame... If anybody has used a koni omega film back you know how cool the film advance is... Check it out: (excuse the lone piece of tape at the bottom i'm glueing a tripod socket as I was taking the pics) Shot counter: The test shot negs: Pinhole scan: not to bad for my first try?