| These large finderscope/photoguide telescope mounting rings mount a short focal length refractor optical tube on an optional Vixen-style dovetail plate. They let you use the refractor as a high power/variable power finderscope for your larger telescope; as a photoguide scope for long exposure deep sky photography; and as a wide field astrograph. The rings are sold as a pair only. They have a nominal 95mm (3.75”) internal diameter and will hold optical tubes with an o. d. of 1.7” to 3.5”. There are three large hand-tighten adjustment screws with non-marring Delrin tips in each ring. These allow you to collimate the refractor with the main scope optics when it is used as a finderscope, or to aim the refractor off-axis to locate an appropriate guide star or photographic target when it is used as a photoguide or astrograph. The rings weigh 1.25 pounds per set. The height from the top of the dovetail plate to the center of the rings is 2.8”. They mount on a Losmandy D-series dovetail plate with no tools required. |