Chicago x, is there any chance of doing a run of 20mm to 17mm copper/brass adaptor rings to sell on? I’d be in for a few if possible. Brass would be fine for me and possibly easier to machine.
Wow! Now that's the way to do an aspheric! Plenty of thermal mass there too with that huge pill! Very nice machine work, and I'm glad that new toy of yours isn't sitting unloved in the shop .
Good stuff, and am looking forward to the lux numbers.