Hi vladimir, Wednesday, March 2, 2005, 9:23:08 PM, you wrote: s> Loweday. It is a 2-mirror 3-reflection design, in which concave secondary vs> reflects light back to the primary, which sends it through an opening on the Concave secondary, or convex? -- Best regards, Richard mailto:cnc@cncservo.co.uk _______________________________________________ ATM mailing list http://www.atmlist.net/