Thread: Lens polishing

Possibly find that the lenses are 'doublet' as dual spehrical grinding of lenses (both sides curved) is a fairly modern thing. The old way is a pair of flat pieces of optical glass, ground on one side and then the flat sides glued together with something called canada balsam - I dunno what it actually is but it's a naturally derived glue that's reasonably optically clear when new. It does break down over time (several decades) and when it does it goes opaque and milky.

What's required then is a full strip down of the device, lenses out, separated and then reglued using modern UV-setting type glue like the dentistry stuff. It's painfully exact work, and not a lot of people do it now (if I was being a wag I'd say that those that are left that can do it are in need of a stripdown, full service and reassembly/reglue with new modern parts as well). I got a couple of scopes redone by an older gentleman in Auckland about 15 years ago - unobtanium to get spares and I talked to him about making a spare set. He laughed. Grumpy old coot... I doubt he's still working now to be honest.