Quick one:
I've got an old 8.75" mirror form an old Newtonian and I'd like to get a second opinion on the figure of the mirror.
I've a rough idea how to do it myself but the experience of someone that has already tested mirrors would be valuable.
It was previously in an OTA with a very primitive cell (bonded to an aluminium plate with epoxied felt) and my startesting at that stage pointed to a turned down edge and astigmatism. Now that it is free of the cell, I want to test it for suitability for another project that it may be useful for. The surface coatings have deteriorated after about 20 years in bad storage, and I want to see if it is worth realuminising or getting it refigured.
Anyone have any ideas?
It'll take me a while to build a foucalt tester, i'd prefer not to unless I have to.
Thanks
Cathal.
  