russell slusher

I don't know why people are not mentioning it. With a large Dob that is an F-4.5 you need a coma corrector. GSO (in Taiwan) makes a very good 2" coma corrector. They make them for several different brands. I bought one for my 14" Dob. AgenaAstro sells them. for $115. I recently bought a 180mm Maksutov. I'm going to do a side-by-side comparison viewing of the planets when we get some clear sky.