Made specifically with the Askar 108mm f/5.6 quintuplet astrograph in mind, The Askar FRA 600 f/3.9 full-frame focal reducer minimized the effective focal ratio by a factor of 0.7x. Equipped with 4 lens elements and with a backfocus of 55mm, this reducer will take your f/5.6 scope to a f/3.9 system, leading to a wider field of view and a reduced exposure time. Capturing wide-field images of large celestial objects in deep space has never been easier. The threads of this reducer are made for M48X0.75 (2") filters. 

• We recommend pairing this with the Askar FRA600 4.3" 108mm F/5.6 Quintuplet Petzval Flat Field Astrograph

• Askar F3.9 Reducer for Askar FRA600 108mm Astrograph
• Adapter