8x10 Pinhole?

[james andrews]

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!

James

 

[shinn]

mrpinhole.com has a handy calculator for determining everything.

Happy Days

 

[ElrodCod]

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.

 

[esearing]

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

 

[james andrews]

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!

James

 

[John Koehrer]

Another good source book for pinhole is: "Pinhole photography" by Eric Renner. Sometimes it's nice to have a paper manual to gander at.