Monopole writes “This is a telescope constructed from the combination of a Russian “Tourist-FL” eyepiece which accepts M42 (a.k.a. Pentax/Universal) manual screw mount lenses a 2x teleconverter and a Russian Lytkarino 3M-5CA 8/500(f/8 500mm)Maksutov Catadioptric Lens.. I constructed it for less than $100 using surplus and parts obtained over eBay.
The resulting telescope has an 111x magnification with “right side up” imaging, without the teleconverter the magnification is 55x. The telescope is nearly free of abberations.
Given the extreme magnification it is necessary to mount a “red-dot” paintball gunsight on top to aim it.” – Link.