In catadioptric astronomical telescopes, the focusing mechanism moves the main mirror itself back and forth. When switching from one direction to the other, the mirror tilts slightly, making it slightly more difficult to focus accurately. There is a solution to this problem, as the TS-Optics 1:10 Microfocus Monorail Coil SC scope replaces the mirror-moving focuser with a more powerful version of the precise, fine-movement Crayford system used in lens binoculars.
The Monorail system allows for stronger, more precise alignment than the Crayford system because instead of small ball bearings, a solid stainless steel rail is used, with only the lateral guidance being taken up by the ball bearings. These bearings only support the lateral position and no longer have to take a load, the load is taken by the steel rail.
The eyepiece can accommodate 2" eyepieces, but can also be used with 1.25" eyepieces with a smaller eyepiece with the included 2"-1.25" adapter. The focusing eyepiece is basically designed for Schmidt-Cassegrain binoculars, but optionally it can also be mounted on Makszutov-Cassegrain binoculars using an SC-MC converter.
