No filters; f/8 is fixed aperture on my old 500mm Reflex-Nikkor. Set D300 to aperture priority, of course (no choice there), and used spot metering. Mounted on a tripod. Exposure was surprising short. About 1/160th, as I recall.[/QUOTE]
Thanks and 1/160 isn't really surprising given that, as I stated eariler, the moon IS a sunlit object even given its distance, esp. when full. Note how well one can see under a full moon at night when in an area free of artificial lighting. I've shot as fast as 1/250 at F5.6 (which works about the same given the bigger f-stop).
I was told years ago that with ASA100 film one would get the best moon pictures at f8 and 1/125 sec. That was standard for daylight.