I'm getting the stuff ready to put together a 8x10 pinhole camera made from wood. I'm thinking that 12" is the proper distance from film to hole at least if I get the hole the right size? Is there a premium distance in regards to film from hole distance? Thanks for any assistance, 44 and this will be my first attempt at putting together a pinhole camera, well actually it'll be the first time I even tried one!
mrpinhole.com has a handy calculator for determining everything.
Conventional wisdom has the diagonal measurement as the "normal" "focal" length. Your length of 12" is about "normal". Most pinholers prefer wider angles than normal. If it were my camera, I make it somewhere between 6" & 9". You might want to check out the f295 pinhole forum.
I've been considering the same here is what I have for 8x10.
Min Focal Length is 7 inches with optimal pinhole at .56mm - f=317
the fstop rises with increased focal length from 317 at 7in to 412 at 12 inches.
Consider building at 9 inches with a 2 inch reversable lensboard as an accessory. Then you have 7,9,11 inch focal lengths so you can choose the best angle of view.
F Pinhole Angle Fstop
7in .56mm 85 317
9in .64mm 71 357 (8 stops > f22) (iso 100 sunny 5seconds)
11in .70mm 60 400
Thanks for the replies it really helps. I was thinking about going wider and having a reversable lensboard which I already have is a great IDEA!
Another good source book for pinhole is: "Pinhole photography" by Eric Renner. Sometimes it's nice to have a paper manual to gander at.