I have a 130mm apo refractor, and I want a Baader neutral density filter for use with it for (some) lunar observing. The question is, which Baader neutral density filter?
I'm thinking either the 0.6 neutral density filter (25% light transmission) or the 0.9 neutral density filter (12.5% light transmission). Comments? Suggestions?
I know that I can get by without a neutral density filter, but I have already made the decision to get one to see what it can do for me. The question is, which one?
From my readings, it appears that most "lunar filters" offered for sale (by Vixen, Orion, etc.) are 12.5% light transmission, so maybe I should choose that, but, on paper, 12.5% seems like so little light!