The Skywatcher 0.85x focal reducer / field flattener has been designed for astronomers who want to use the renown ED Apo for astro photography. The flattener reduces the telescope's focal length by the factor of 0.85 and increases the useful field. As a positive side effect, the necessary integration times are significantly reduced. The field curvature that is unavoidable at most telescope systems is reduced to a nearly irrelevant level when using sensors up to APS-C format (24x16mm).
Optimal distance M48 - focal plane: 55mm
Item condition: new and original packed
