FLAT6AIII special edition for Fluorostar 91

Finally got this attached to my Fluorostar 91 and the stars across the whole frame are perfectly round now. The machined aluminum ring feels solid and threads on smoothly.

It cleaned up the coma in my Fluorostar 91’s corners immediately—first shot with it and the stars looked like pinpricks across the whole frame. I’ve been fighting with edge distortion for months, and this accessory finally made those test shots usable without cropping.

Finally got clear stars all the way to the edge of the frame with this flattener—my previous setup always left soft corners. The threads are butter-smooth and mate perfectly with the Fluorostar 91's focuser, no wobble at all.