TAKAHASHI 645 SUPER REDUCER FOR CCA-250

The Takahashi 645 Super Reducer is a 0.72x focal reducer for the CCA-250 corrected-Cassegrain astrograph. The 645RD reducer has a large image circle of 60mm, making it suitable for use with medium format sensors. The 0.72x reduction factor reduces the focal length to 890mm and focal ratio to f/3.6, transforming the CCA-250 into a high performance super astrograph.

The 645RD Reducer consists of four large-diameter lenses in four groups, giving illumination of more than 70% at the edge of the field. The illumination over a 44mm diagonal (such as that of a full-frame sensor) is more than 90%. The lenses are coated with broad-spectrum multi-layer coating, reducing reflections and increasing transmission over the visible range.