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Posted By: Walt Mathers on: 01/20/2008 16:19:27 EDT|
Subject: Telescopes Having Foggy or Dirty Lenses
"... having difficulty focusing the glass - ... can see colors but nothing is in focus - ... are the optics messed up?"
You may have one of the optic glasses missing but, then again, perhaps the glue attaching the two-part lens glasses in one or more of your lenses may very likely have crystallized. If the latter is the case, you can't polish it away since the glue is sandwiched between the two pieces of glass. You will be able to detect if this is the case once the sections of your glass have been dis-assembled and each lens inspected.
Seeing colours but everything is out-of-focus (foggy too) happened to a period marine glass. I was blessed with having another signal re-enactor (who also happened to be an optometrist - before he retired) apply heat in order to separate the joined pieces of glass and join them again with fresh glue.
Despite all the correct storage practices, 140 years can change a lot of characteristics of such instruments - even under what might apprear to be the best of conditions.
Signal Corps Association (1860-1865)