Originally posted by BigMackCam That's exactly what this is - a catadioptric telescope with an F-mount.
But a good Newtonian telescope at 2000mm costs a lot less than that lens which is why I was wondering if going the telescope route would be better. There are some very good reflectors that don't carry the Nikon name and thus aren't $32,000. It looks like for about $
8,000 you can get a 2000mm f/3.9 scope with goto mount which would seem to be money better spent.
Originally posted by BigMackCam I have a Soviet MTO 1000mm catadioptric lens
I also have in my possession this lens as it is on semi permanent loan from a friend who go in trouble with his wife and needed for it to live somewhere else. It is M39 mount and to get the clearance from the popup flash I have to stick a teleconverter in the mix so I use it at 2000mm and f/20. It is big, fun, and of limited use