William Optics Flat73A Flattener for ZenithStar 73

William Optics Flat73A Flattener for ZenithStar 73

A 1.0× field flattener that preserves the telescope's native focal length for the manufacturer's listed refractor combinations. Its optical system uses 2 elements in 2 groups.

Mechanical interfaces

The telescope connection is M63x1; the camera connection is M48x0.75. Weight is 328.8 g. 39.5 mm flattener plus 26 mm rotator/adapter.

Spacing and telescope selection

For ZenithStar 73: 66.2 mm backfocus, with 11.4 mm adjustment and a 43 mm image circle. Use the listed front or rear adapter where specified; backfocus and mechanical adjustment are different measurements.

William Optics manufacturer specification and compatibility chart

Compatibility notes

Spacing and mechanical fit require exact interfaces and reference surfaces. Named standards do not establish every system combination.

Additional specifications