Hi Chuck, I'm wondering if you could give me a bit of advice. Recently I shot eyepiece-projection first quarter moon photos at a variety of exposures with a 26-mm eyepiece, using my new 12". With 200 ISO film the best exposures seemed to be about 1/8 second, possibly 1/4 but more likely 1/8. When I get around to it, I want to do some more moon photos and Mars photos. Could you help me figure out how the exposure varies with eyepiece projection, using different powers of eyepieces? I have a fair number but I don't recall all their sizes right now. And I assume that first and third quarter exposures would be about the same, but what about other times, such as waning crescent going toward new moon? Can you describe some easy formula for calculating exposure change with different mm. eyepieces? If not, assuming I work up the energy, I'll just go out and shoot a variety of exposures. Also, what kind of exposure do you recommend for Mars? Thanks, my friend -- Joe Joe Bauman science & military reporter Deseret News bau@desnews.com (801) 237-2169