Hi all, in the search for a good Newtonian telescope I'm buying next summer I stumbled accross Orion Optics Uk and will most likely be buying from them. One option to the optical sets or OTA's is a zerodur mirror instead of pyrex. What's the benefit from zerodur? Wouldn't I be better off with the other option; 1/16 surface accuracy , 1/8 PV wavefront? I can't afford both options unless maybe for a 10" aperture but I really want a 12-14".
Thanks
Nico
Thanks
Nico