Golden age of Singlet lenses
The 18th century lens from a german mirror has arrived safely to me after a month of waiting. The diameter 101mm the lens was grinded on one side and polished on both but a little on the flat side to remain the old felt original polish from the 18th century. Tested on auto-collimation foucault showed a good spherical surface after re-polishing, similar to Campani lenses being a Campani lens as good as new in early days. The Venetian glass being very good and was easy to re-polish. Some little defects at the edge and something extremely slightly visible in the center as a small bulge that does not influence barely visible in the auto-collimation foucault test. Overall looks like freshly made Giuseppe Campani lense. The edge had to be beveled a lot because of the chips, it was decided to cut it to 101mm, it can be used at 93mm to 85mm diameter. The lens perfectly resembles that of Giuseppe Campani from the Museo della Specola Bologna having about the same focal length 12m, the...
