----- Original Message ----- From: "Philip willarney" <pwillar...@yahoo.com>
snip >the focal length is about 40 mm, and I > haven't figured out an exact f-stop for the pinholes > yet). > > Use ASA 100 film > Bright sun: 2-4 seconds Philip, Usually it is the other way around, you figure out the times based on your aperture, and you find the aperture either by: 1-shooting and taking notes until you "know" your camera and based on that find the aperture, or 2-by measuring the pinhole diameter http://members.rogers.com/penate/diameter.htm In any case, based on your Bright sun exposure of 2 - 4 secs, the camera(s) should have an aperture of around f/180, that, in turn, dictates a pinhole size very close to the so called "optimum size". If I were you, I'd measure the pinholes, find the f/stop and then come up with the exposure table. I find that the easiest way to maintain or creating enthusiasm for something is by having success from the start and a good exposures table is surely a way to help your relatives to succeed from the beginning. Guillermo
