full-frame Reducer for FRA600

The reducer shortens the focal length of the Askar FRA600 Quintuplet Astrograph. This reduces the exposure time and makes the optics "faster". It also increases the field of view.

The 0.7x reduction gives the FRA600 Apo a larger aperture ratio of f/3.9 instead of f/5.6 and thus a significantly shorter exposure time. The reducer is simply inserted into the focuser.