FLAT61 1x FLATTENER FOR ZENITHSTAR 61

The William Optics Flat61 is an apochromatic 1x field flattener for the Zenithstar 61. The 43mm image circle makes it a good match for full-frame sensors. 

The Flat61 features adjustable spacing for use with a range of cameras and imaging systems. The Flat61 includes an M48 filter thread which will hold any standard 2" mounted filter. It also includes a handy camera rotator for precise framing of targets.

Compatible with William Optics Z61 which has an M54 x 0.75 thread. On the camera side there is an M48 x 0.75 male thread, which will accept any wide T-ring (sold separately).

Note: As this is an adjustable flattener, you must adjust the distance for your specific telescope. See the Instructions tab above.

Specifications

Instructions

Note: Once you have unscrewed the rear adapter to the appropriate value in the table below, the remaining backfocus distance to make up will be 55mm from the rear M48 thread.  

Distance adjustment needed for correct backfocus