Guys- I figure this question has been asked a hundred times before but...
I have a 16" Dob and on the occasion I want to look at planets or the moon with it I'm using a moon filter from a celestron 2" eyepiece set. I have another filter for 1.25 inch eyepieces, both seem to create an annoying internal reflection and at least for the moon isn't really cutting the light enough!
Perhaps I need to get something like a polarising filter.
Yes, I know that looking at the moon with 16 inches is like the old proverb of diving for golf balls with a sub, but If I'm surfing the sky and I suddenly feel like catching a moon or planet, setting up the 8" scope as well is proving to be more trouble than it's worth. Plus I can only cart one or the other to dark skies anyway.
Suggestions or filter recommendations much appreciated!
GSO Moon filters work quite well for me. No real internal reflections. Reasonably priced with reasonable build quality. For a 16" scope you'll want one that reduces as much light as possible. I use a 90% reduction one in my 12".
I believe the best option is a polarizing filter. With my 14" scope a 13% ND filter is too bright for my eyes. I gave a try to the Antares 1.25 variable filter (got it from scopestuff.com), the polarizing feature was very good, I could make it as dim as I needed, but the optic quality was very disappointing. I'm still looking for a good polarizing filter for my scope.