FLAT6AIII 0.8x REDUCER FOR GT71, GT81, Z81, Z103

The William Optics Flat6AIII is an apochromatic triplet 0.8x flattener/reducer with STM-coated Ohara lenses. The 44.4mm image circle (43.1mm with the Z103) makes it a perfect match for full-frame sensors.

The Flat6AIII features adjustable spacing for use with a range of cameras and imaging systems. The Flat6AIII includes an M48 filter thread which will hold any standard 2" mounted filter.

Compatible with William Optics GT71, GT81, Z81 & Z103 telescopes which have an M63 x 1 thread. On the camera side there is an M48 x 0.75 male thread, which will accept any wide T-ring.

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

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