Can anyone tell me the OD of both the 2" and 2.5" moonlite newtonian focusers?
I'm considering upgrading the focuser on my GSO 200mm f4 (which has the stock 2" ID focuser) and so am using the OWL Diagonal calculator to work out the field illumination at different points in the optical path from the secondary to the focal plane.
I'm also unsure as to whether the drawtube of the 2.5" moonlite would fit through the existing hole in my optical tube. i realise I would most likely need to drill new holes for the mounting screws, but im not sure how I would go about increasing the size of the main focuser hole if that was required (from say 3" to 4") and in that case it would probably be easier to just go with the 2" moonlite which is a simple direct replacement.