Of course we all are on a first name basis with the sunny f16 rule but have you heard of the loony f4 rule? This is a serious question. I never heard of this rule and I've read a lot of books etc. For anyone else who never heard of it, it is apparently a basis for exposure under a full moon and the formula is this: 1/film speed x day. 'day' = 864000 which is the number of seconds in a day. So for ISO 100 film, you would have 1/100 X 864000 = 864 seconds or 14.4 minutes at f4. Now if you have heard of this rule, do you know if there is a formula for half, quarter and eighth moons? Greg Fraser http://users.imag.net/~lon2251/Gallery
