This clever accessory makes it possible to have a dual focal ratio instrument, without sacrificing image quality. If offers wide fields of view with any Schmidt-Cassegrain telescope. Used for astrophotography, it reduces exposure time by a factor of 3.
Results are amazing both visually and photographically.
This accessory makes it possible to simultaneously photograph and guide through the optical tube assembly of your telescope. The Radial Guider also eliminates the problem of differential flexure, because you're both guiding and photographing through the telescope. Primarily for use with catadioptric telescopes, but also works on refractor telescopes having adequate back focus. This guider is a tremendous improvement over conventional off-axis guilders. Not only is the angle of the prism tunable, but it also maintains a fixed rigid camera orientation while still offering users the freedom to move the guiding eyepiece radially about 135 .