Posts Made By: Bernie Kosher

having trouble. central 8" of mirror shows good sphere, but is then far too flat to the edge. cannot get it to go spherical. have done mirrors but this ones got me. tried many stroke lengths and pressures. using 8" lap with 1" diamond shaped facets. Googol 64 pitch. cerium oxide. can send Ronchigram if needed. embarassing, as I have done a few of these types. help. thanks.
Bernie

Anyone have any idea of the value of a 12.5" pyrex full thick mirror marked "refigured by Cave etc" in 1967 with serial number and test data slip?
Coating is shot but the figure is excellent.
Thanks
Bernie

Anyone have any idea of the value of a 12.5" pyrex full thick mirror marked "refigured by Cave etc" in 1967 with serial number and test data slip?
Coating is shot but the figure is excellent.
Thanks
Bernie