Askar 1x Full-frame Flattener for the 140 APO - 140APO-FLAT

This Askar 1X Full Frame Flattener is designed specifically for the 140APO.  It does not change the effective focal length of the telescope, which is f/7, but it DOES further flatten the field, correcting for both field curvature and coma, to reveal fine star points to the edges of the field.  

The Askar 1X Flattener has a triplet design and supports a 44 mm image circle.  The telescope side has an M91*1 thread, and the camera side of the flattener has a built-in M48x0.75 (2") thread to accept filters and comes with three adapters (M68*1, M54*0.75, and M48*0.75).  Both ends come with threaded metal caps to protect the optics when not in use.

SPECIFICATIONS

Lens Design:  Triplet

Back Focus:  55 mm from base of M48 male threads

Telescope Focal Length with Flattener Attached:  980 mm

Telescope Focal Ratio with Flattener Attached:  f/7

Camera Side Thread Types:  M68*1, M54*0.75, M48*0.75