Ad Astra Observatory

style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid">Hi
Ron,

A Stiletto will definitely help you to find focus if you’re using
a telescope. I did not find mine all that useful when trying to focus a SLR
lens, though; tehre are a number of issues to contend with, there, including
how to mount the lens to accurately point at something, achieving really nice
focus with a helical focuser, and how to pick out a particular star to focus
on when the FOV is so huge.

I often use diffraction spikes to focus
accurately; if the telescope doesn’t have a spider, then attach a pair of
strings or wires across the front of the dew shield of the scope, then shoot
some photos, and analyze them on your PC. At the point of best focus, the
diffraction spikes will be as small and sharp as possible and there will be 4,
not 8. Once you’re in focus, you can leave the strings on while shooting (I
think the spikes look pretty in images) or remove them.

I shoot with a
Nikon D70. Works great.

I hope this helps.

Best,
Jimbo S.
Harris
Newark, CA