Hi all
I'm looking for a helical focuser to assist in fine focusing. Ideally non-rotating, but will accept a rotating one.
There's seemingly a huge array of these things and a bit confusing how to attach to the scope.
I'm looking for either a 1.25, or preferably a 2" version, that simply fits into the standard 1.25" or 2" eyepiece slots. Alternatively something that screws directly onto the focuser of my scopes (but how to know what thread those use; have several scopes all with different threads?)
Also: since these devices obviously lengthen the path, do they actually work for visual on refractors and Newt's? (assume CATs are fine since the mirror moves)
Am lost in the woods atm in terms of threads and diameters, etc. Help?!