The Moon
Uncropped picture of the Moon taken near the winter solstice.
Copyright Bertho Boman 2005

"After seeing many moon pictures I wanted to try to get a good picture myself. After a few test, I found the perfect focal length to match the sensor size in my Nikon D2X; 1250mm.

1250 mm does not sound like any easily obtained focal length except using a 600mm lens with a 2X extender. That would be a very expensive setup! As an alternative, I found the perfect focal length by using a Meade ETX telescope. The lens diameter is 90 mm and it has a focal length of 1250 mm which gives a rather slow f=13.8. As a result the exposure was 1/60 second @ 400 ASA which was longer than optimum.

To get better resolution would require dryer atmosphere than in South Florida and a larger aperture to get faster exposure. A tracking mount would also reduce the speed requirement.

The 600 mm f4 Nikon lens + 2X extender would become 1200 mm f8. That would probably be a safer focal length because the moon just barely fits in the picture using the 1250 mm focal length.