I have a Newbie question about filters. I want to get a moon filter and was just wondering where/how I attach it. From what I have read it screws onto the EP. Where? None of my EP's have a thread where I would think of putting a filter. Do I need a special EP with a thread? Or does it screw into the focuser somehow?
P.S. From memory my local shop has a gso moon filter for $25. Are these ok?