William Optics Flat73A Flattener for ZenithStar 73

William Optics Flat73A Flattener for ZenithStar 73: the calculated flattener for your ZenithStar 73

The William Optics Flat73A is the field flattener designed for the ZenithStar 73. Every refractor naturally produces a slightly curved field of focus; a flat camera sensor cuts through this, causing stars in the corners to stretch into streaks. A flattener corrects this curvature, ensuring stars remain small and round all the way to the corners. Especially with this fast doublet and larger sensors, the correction makes the difference between soft and sharp corners.

You screw the flattener directly onto the focuser: no loose adapters, no wobbly clamp connection. The scale-marked adjustment ring sets the backfocus; once found, you dial in the same value each session.

On the train

The camera side is M48; with the William Optics M48 adapter for your bayonet, the sensor is directly at the correct distance. You screw M48 filters directly onto the flattener.

Featured accessories

Connect your camera using the M48 adapter or 48 mm T-ring for your cameramerk.

For whom yes and for whom no

• ✓ ZenithStar 73 owners who photograph
• ✗ ZenithStar 61 owners: the Flat61R is designed for you

Specifications

You can find more accessories for this merk at the William Optics merk Page.