On Jan 7, 9:02*am, RMOLLISE wrote:
On Jan 6, 5:26*pm, "Mickman" wrote:

Can you get a new secondary mirror for a C8 thats at least 10 years old?

You might find a secondary surplus, but it is unlikely it will work
well. Celestron applies figuring to its secondary mirrors to bring the
optical systme fully within spec.

What figuring? Surely the mirror just needs to be flat and mounted as
stress free as possible.