|
Last I knew, stephen svensson (sopticals dot sas at hotmail dot co dot nz) in Oamaru, new zealand had a 640mm dia, 37mm thick, f5.3 mirror for sale. It did not sell at NZ$1100 (9 june). He says (and the ronchigrams seem to show) maybe the outer 25mm is slightly turned down .
even with the outer 25mm masked it's a nice big aperture, but you'll need a ladder.
|