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| The mirror is ready to be shipped from H.K. Please understand that the surface delivery is/might be a great value, but it does take LONG time, as long as 10 weeks (or even longer). You agree not to make the delivery time an issue by using the surface delivery. Please wait for our invoice for the exact shipping cost.
This is a professional fabricated, brand new, top quality 0.75" thick plate glass, F/5.0 primary parabolic telescope mirror. It is tracked by S/N 09-05-08-45, with the individual test result given below. Please note that our PV (Peak to Valley) test result is given in wavefront profile, not the surface profile. The minimum PV of the surface profile rating should be 1/8 lambda, the minimum PV of wavefront profile rating should be 1/4 lambda. Optical Aperture (Diameter): 8.00" Coating: The standard aluminum coating with SiO protection overcoating, 88% reflectivity Radius of Curvature (ROC): 79.62" Focal Length: 39.81" Wavefront PV: 1/9.9 Lambda RMS: 1/34.1 Lambda Strehl Ratio: 0.97 Please provide your phone number during check out. FAQ : (1) Is there any performance difference between mirrors made of Pyrex and mirrors made of Plate glass? The short answer is, believe it or not, there is none. You may want to read Four Infamous Telescope Myths by Gary Seronik at: http://skytonight.com/howto/visualobserving/3305656.html?page=2&c=y The article only evaluated small mirrors, but the conclusion is actually true regardless of the size of the mirror.
You may also want to read: http://www.mtwilson.edu/vir/100/mirror/ This is the site for the 100" plate glass mirror of Hooker Telescope, the largest solid glass mirror ever built. If those bubble filled, layered, plate glass has been good for the 100" solid glass mirror for almost 100 years; our top grade modern day plate glass with far much better quality must be good for a much smaller and much better structured mirror. The 100" Hooker mirror does take much longer time to cool down than the 200" Palomar telescope mirror. But this is primarily because the much more efficient honeycomb structure is used in the Palomar telescope mirror.
You can learn more on this on our web site: http://www.hubble-optics.com/products.html
(2) How to fit the mirror into an old "cup" style mirror cell, which is a few mm smaller than the mirror? One way is to use a mill or lathe to enlarge the cup of the mirror cell. The much easier and better way is just cut off the side of the cup; you really do not need the cup, nor the clamps. Just use RTV to glue the mirror to the mirror cell's support pad. You end up a much better mirror cell.
(3) What size secondary mirror should be used with this mirror? The size of the secondary mirror depends on many factors. Here is the formula of the diameter of minor axis of the secondary:
Normally, a secondary with about 1.89" minor axis diameter can be used with this mirror. What our customers are saying: Last night I had “first light” with the 12.5” f/6 mirror that you recently supplied. It is truly a magnificent optic! Ronchi, knife-edge, and star tests were straight out of a textbook, and the image of Saturn was breathtaking. Despite the thin substrate, there is no hint of astigmatism. Frankly, when I purchased a Hubble Optics mirror on eBay, I was skeptical of the advertised wavefront quality. For the low price, it just seemed too good to be true. In the future, I will not hesitate to recommend your firm’s optics to friends and acquaintances. ......
I’ve tried buying fast 8” mirrors twice through A-mart and both were dogs – terribly undercorrected, probably spherical. This mirror is way different. Stars are near pinpoints and there is no tendency to astigmatism (at least nothing that didn’t come from my eyes). I went out tonight and looked at Jupiter as soon as it became visible. Even so, it is getting pretty low in the sky and the air was pretty wavy. As near as I could tell, in the moments of stillness the images were as good as any scope I own. Dave Chadsey
I just tentatively assembled my 10" F4.7 1/17 PV wavefront mirror in my observatory and watched Jupiter and the moon last night. Although the air condition was terrible due to middle of rainy season, optical performance was exactly as I expected! The surface of Jupiter was amazing. Contrast of color was deep and details were very sharp, image edge was knife cutting, even through hazy bad seeing. The surface of the moon had an extra contrast; very very sharp edged landmark was attractive enough to keep watching hours. A hair splitting and breath taking experience, which reminded me of previous mirrors. I need to further tune up optical performance of this scope such as replacing with smaller high precision secondary mirror etc. Will report further progress.
Kazuki Yamane
More eBay Feedback we have received (Over 400 great reviews!)
WARNING!!!: NEVER LOOK AT OR HANDLE THE MIRROR UNDER THE SUN! THE REFLECTION OF THE SUN LIGHT MAY CAUSE BURNING OR INSTANT AND IRREVERSIBLE DAMAGE TO YOUR EYE. EYE DAMAGE IS OFTEN PAINLESS, SO THERE IS NO WARNING UNTIL IT IS TOO LATE. CHILDERN SHOULD NOT BE ALLOWED TO HANDLE THE MIRROR. |
Shipping and handling Item location: Hong Kong, Hong Kong Shipping to: Worldwide
*The estimated delivery time is based on the seller's handling time, the shipping service selected, and when the seller receives cleared payment. Sellers are not responsible for shipping service transit times. Transit times may vary, particularly during peak periods.
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