My pinhole camera is a 120 film box camera (a Sunbeam found at a garage
sale) with the (single element) lens removed, and a small metal sheet with
a hole drilled through it (acquired from Pinhole Resources as part of a
set). The metal sheet is very thin. (You can use brass shim stock bought
>from a hobby store, 0.002" or 0.003", to make your own.)
I'd take a peek at "The Penultimate Pinhole Page" (found at
http://www.airtime.co.uk/pinhole/). The Pinhole Resource On-Line (at
http://yatcom.com/pinhole/pinhole.html) can't be found by my current
nameserver.
I should mention that I use T-Max 100 and T-Max 400 for B&W work,
since there's no adjustment to developing needed for long exposures.
Some of my exposures are in the 10- to 20-minute range, depending on
lighting conditions.
David S. Cargo