MTO - MTO 1000A disassembly

This technical guide provides comprehensive step-by-step disassembly instructions for the MTO 1000A catadioptric lens (F 10/5, 1100mm focal length), authored by Jonathon St.Onge. Addressing the scarcity of detailed documentation available online for Soviet-era telephoto lenses, this manual offers precise procedures for dismantling this M42-adapted optical instrument. The guide opens with complete technical specifications: M42 mount, 120mm filter thread, length ranging from 240mm (closed) to 300mm (extended), and comprehensive equipment requirements including flathead screwdrivers (1mm, 2mm, 2.5mm), a spanner wrench up to 120mm, and recommended lubricant (MicroLubrol Helimax-XP). Subsequent sections methodically examine critical components: the notched retaining ring (120mm diameter, 114mm inner thread), the M42 mount mechanism featuring two sets of retaining screws, and the inner and outer rings of the rear assembly. Detailed photographs accompany each section, documenting precise screw dimensions and component specifications. The manual specifically addresses the locking mechanism of the rear assembly, explaining the counterclockwise unscrewing procedure and the adjustment mechanism for sight alignment. This resource proves essential for optical technicians and vintage lens enthusiasts seeking to service, repair, or restore this demanding catadioptric design, offering practical guidance previously unavailable in accessible form.