Today, we unmounted the big telescope: first the primary mirror, then the secondary and finally we took the “skeleton” (the truss-tube) of the mount.
And we were in for a big surprise: once we cleaned bit mirrors (very very delicately, first removing all the dust under running water – and then cleaning it with an oh-so-soft soapy water) both looked almost perfectly! No oxidation, nor any other deterioration. They are almost as good as new!
The corrector (Philipp Keller, ASA) reducing the focal ratio to f/3.3The Keller-corrector, here seen next to the huge Apogee-camera for size-comparison.