WILLIAM OPTICS FLAT 61A

William Optics Dedicated Field Flattener for Z61 APO Telescopes

Designed specifically for the William Optics Zenithstar 61, this precision-engineered flattener is optimized for astrophotography with this compact APO refractor. It is not compatible with the Star 61 guidescope.

Optimized Optical Performance

This dedicated field flattener delivers a true 1:1 optical correction—meaning there is no focal length reduction—preserving the full 360mm focal length of the Z61 while flattening the image field for full-frame imaging sensors. The design ensures sharp stars from center to edge with an image circle of up to 43mm.

Telescope Connection (M54)

On the telescope end, the flattener features a male M54x0.75 thread to directly attach to the Z61 focuser drawtube. Simply unscrew the 2" eyepiece adapter on your telescope to expose the internal M54 female thread for proper connection.

Camera Connection (M48)

The camera side includes a male M48x0.75 thread, designed for use with M48-format DSLR or mirrorless T-rings (sold separately). Please note: M42 T-rings are not compatible with this flattener.

Built-in Rotator for Framing

A standout feature of this field flattener is its integrated camera rotator, allowing easy adjustment of your imaging orientation without requiring a separate rotator. Frame your subject perfectly with smooth rotation right out of the box.