Taking photos of a Full Moon

Can anyone give me any suggestions of taking pictures of a full moon. I usually take 100 ISO print film, with a long exposure on a tripod. When I look into the view finder the moon is perfectly focused but when I get the prints back it is just a fuzzy white circle. Is my exposure too long or should I use a faster film?

thanks
Dan

Your exposure is too long. Actually, you can use an adaptation of "sunny 16" to determine exposure, but add one stop.

If you're not familiar with that, it basically says that in bright sun (the moon itself is lit by the sun and since it's the subject of the photograph the rule still works), you can expose at the reciprocal of the ISO speed at f16. That just means "one over the ISO speed" and f16. Since you have ISO100 film, the closest shutter speed is 1/125. Since you want to add one stop, use an aperture of f11 and it will work just fine.

BTW if you're shooting 35mm, the full moon will be about 1/100 of the focal length on the negative. A 500mm lens will give you a 5mm diameter moon on the piece of film that's 24mm x 36mm. You can see it takes over 2000mm (i.e. telescope) to go full frame with it...

I've done a few shots of the moon, and if you want a quick and easy rule of thumb, just subtract 2 f-stops from the exposure. E.g., if you're shooting 100 ASA film then set it to 400 for those shots. That should get you some good details of the moon.

Also, better watch your exposure time: the moon does move, and it will blur if you use too long an exposure. You should set your apperature to wide open or something very close to that, which will maximize your shutter speed. If the moon is low on the horizon then this may not be such an issue (it won't appear to move as fast).

Finally - just an added tip. If you're looking for shots where the full moon is low on the horizon, shoot the day before or the day after the night of the fullest moon. I heard someplace that the full moon night it will be directly above but that the day before and after it will be lower on the horizon (no idea why)...

Thanks for the advise, I will definitely try those techniques