My Meade 4000 series is now OK with C11 after re-assembly (not ideal but acceptable and probably within design specifications..), but I am still thinking about that binocular objective lens.. (the other, objective from theodolite was very bad)
I decided to do some more tests with better setup.
Using
this M48x0.75 to M42x1 adapter (after machining it a bit so the lens fits inside nicely), I will try to play with working distance to optimize the coma in corners of the APS sensor. Hopefully the weather will cooperate..