I'm in the planning stages of an 8X10 pinhole build. I've found most of the links on other threads on pinhole calculators, the one with the 4X5 dimensions (which I've scaled up to 8X10) etc. I will be utilizing paper negatives in this camera My biggest question - what is the best way to hold the film/paper at the back of the camera. I guess the most ideal would be an 8X10 film holder. I don't own one, so unless anyone can point me in the direction of one for ~$20-30, I'll need another alternative. If anyone else has dimensions for their 8X10 build, I'd love to see them. I think I have it figured out, but seeing other designs never hurt. Also, anything you learned while building. No need for us all to repeat the same mistakes! For the actual pinhole, I've heard the thinner the material the better? I have access to tons of scrap lithographic printing plates. I'd have to measure the thickness to be sure. Offhand, I'd say about the thickness of a regular business card.