OTA · 2008– Vixen VMC260L Vixen Optics · VMC260L Key specifications Aperture260 mm Focal length3000 mm Focal ratiof/11.5 Optical designMaksutov-Cassegrain About 260mm f/11.5 VMC modified Maksutov-Cassegrain catadioptric; large open-tube planetary/lunar scope.