I have made lenses before - for a homemade telescope. I did it years ago for the "experience." I used "crown" glass and "flint" glass bought from a scientific supply company. The glass came as flat, round disk pairs, one became the "tool" and the other the lens. I worked them against each other using a fine diamond slurry. One becomes concave, the other convex. Final polishing was by pitch holding something similar to jeweler's rouge on the "tool." No, I had no way to add coatings. It was a very long time ago, but I am told that the process is very much the same today. Machines now hold the "blank" and the "tool" for generating the initial figure, but for fine glass, supposedly the final figure and polishing are achieved by hand. Perhaps some initial figure is achieved by molding of blank and tool. Of course, I may be way out of date on this too.
Regards, Bob... From: "Alexander Selzer" <[EMAIL PROTECTED]> > Hi Jens! > > Am Mon, 28 Jun 2004 07:30:51 +0200 > schrieb "Jens Bladt" <[EMAIL PROTECTED]>: > > > How many lens manufacturers are there in the > > (western) world and who are they? > > If you mean by "lens" not only hole systems, then: many, really many, > dozens. And if you mean systems then still a lot. > > > Does the glass production (raw, > > unpolished lenses) take place in Pentax own factories or do all camera > > manufacturers buy their raw lenses from a few big factories. > > Not all camera manufacturers are making lenses and not all lens > manufactures are making cameras. But normaly the lens manufacturer buys > glass from Schott, Hoya, ... in plates, bars, gops etc. and then there > follows either a molding process or a milling process to make the lens > shape.
