Bryan Stone Past President, NSAAC (North Shore Amateur Astronomy Club) Visual Astronomer with: "GoldenEye" XT8 Classic, flocked, Moonlite CR2(Gold), Telrad, 1st Base mount Serial #001 "Night Hawk" SV 80mm f/7 Aplanat on M1/GNG TV 11NT6, 32P, 1.8xB, Pentax XF 8.5 ES 82 N2 6.7, GSO SV 30, UO KII 16 Lumicon OIII,Orion Ultrablock, Moon Filter, 4 color filters, 25mm Sirius P, 10x50 Explorer Binocs, Celestron broadband filter,Tectron collimation tools, Pelican 1500 Divider Case, StarDust chair
-Brian 14" Hubble Optics ATM Newtonian Paracorr II Ethos Eyepieces VE9WTH
Quote:This past April at NEAF, Protostar announced that they were coming out with drop-in replacement secondary mirror mounts and holders for 8 and 10 inch Synta (Orion) Dobs. There is no mention of this on their online catalog and I just called their tech support line to inquire and found that it is disconnected, and no answer on their toll free order line either.What's up with this?thanks
Quote:The Antares secondaries will not be a %^$# shoot because they are analyzed by interferometry. You will know what you are getting.
Quote: As it was explained to me, they make a large run of secondaries, then test them. Depending on the test results the mirrors are differentiated into the 1/10, 1/20, and 1/30 categories and priced accordingly. If the number of mirrors manufactured is small there may or may not be 1/20+ wave mirrors in the batch.
Orion XT12i with Swayze-refigured primary & Protostar secondary
Televue NP101 refractor
William Optics Megrez 90 refractor
Universal Astronomics Deluxe Mounts
Quote:the mirrors in the standard sizes are produced in large volumes and differentiated by wavefront error during evaluation.
Quote:On the Antares page "more about secondary mirrors", they discuss the difference between PV at surface and wavefront. From what they say there, you'd expect their secondaries to be listed with PV errors at the wavefront:
Quote:Stratocaster,Can you confirm that the PV errors for the secondary mirrors listed on the Antares website are for the wavefront? and not the surface?
Quote: BTW, I just re-checked the Protostar site (I've bought from them in the past and have been entirely satisfied with quality). They specify wavefront -- or seem to -- for their quartz secondaries.Surface flatness is a minimum quality of 0.1 wave peak-to-valley on the wavefrontBut Protostar is the only vendor I've come across that does this for secondaries -- and it may be the case only for their quartz secondaries.
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