William Optics Flat61R 61 Field Flattener for ZenithStar

William Optics Flat61R 61 Field Flattener for ZenithStar: turns your 61 mm apo into an astrograph

The William Optics Flat61R is the field flattener for the 61 mm apos from William Optics. Every refractor naturally produces a slightly curved focal plane; a flat camera sensor cuts through it, causing stars in the corners to stretch into streaks. A flattener corrects this curvature so that stars remain small and round all the way to the corners.

The telescope side is an adjustable M54 connection: you screw the flattener onto the focuser and adjust the distance to the optics until the corner stars are sharp. The camera side is M48, with an integrated M48 filter thread so that your filter is directly in the optical train.

Which telescopes

Made for the William Optics ZenithStar 61 series and the GuideStar 61. In combination with the GuideStar 61, your guidescope transforms into a complete travel astrograph.

Camera connection

On the M48 side, you connect your camera with a William Optics M48 adapter or 48 mm T-ring for your bayonet mount. This places the sensor at the distance for which the flattener is designed.

Featured accessories

Combine the Flat61R with the M48 adapter for your cameramerk; these are listed as separate products in the product lineup.

For whom yes and for whom no

• ✓ Owners of a ZenithStar 61 or GuideStar 61 who want to take pictures
• ✓ Travel astrophotographers with small to APS-C sensors
• ✗ Owners of other tube diameters: every WO apo has its own calculated flattener

Specifications

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