I image using the AT-72ED and AT102ED scopes. I also use the AT ATR8 flattener/reducer on both scopes. I recently bought a filter wheel. Now I dont have enough back focus. Almost, but cant quite attain focus.
I would be able to get focus if I could swap out the 2" focuser adapter that fits on the back of the flattener, but I have no idea what the thread size is on the body of the optics. I'm talking about the end that normally fits into the focuser. If I could find a shorter adapter to replace the 2" focuser piece, I would be able to image with it with the filter wheel. any ideas? TY.