I have a Lentar 500mm mirror lens that appears to have developed an oil film on the secondary mirror. Does anyone have ideas on disassembly and cleaning?
i used to have a 250 lentar mirror - you could just remove the infinity stop screw (don't recall exactly where it was, either under the focus grip or somewhere nearby) and then unscrew the front end right off.
Hhi Jed: can't help take it apart but I had a similar appearing problem on an 8" telescope mirror and it was oxidation of the front surface mirror. Be very careful chances are it is a front surface mirror and very vulnerable to marking and flaking. There is a shop inb P.A that resilvers mirrors but it is not cheap. Don
