Current Price: $3050.00
Buy It Now Price: $3050.00
Bids: 0

It will be ready to ship in about 2-3 weeks.

Please understand that the surface delivery (Economy Shipping) is a great value, but may take longer than 10 weeks for the delivery; however it does have the online tracking and is fully insured. You agree not to make the delivery time an issue and not to open a case based on the delivery time with Paypal or eBay if the surface delivery (Economy Shipping) is used.

Surface(US$)
Air(US$)

US
151
310

US
151
278

Austria
103
224

Australia
N/A
323

Belgium
284
284

Brazil
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Chile
566
566

Canada
95
264

Denmark
80
242

France
96
250

Germany
87
245

Israel
80
215

Italy
N/A
375

Japan
79
146

Korea(South)
N/A
143

Lithuania
N/A
496

Malta
74.6
193

Mexico
327
327

Netherlands
86
221

New Zealand
111
267

Norway
N/A
329

Philippines
59
101

Poland
87
207

Romania
92
221

Russia
N/A
435

Singapore
57
115

South Africa
63
226

Spain
54
188

Sweden
N/A
315

Switzerland
94
242

UK
87
251

This is a state of art,  professional fabricated, 20" F/4.1, revolutionary lightweight sandwich primary parabolic telescope mirror   made of the top quality precision annealed plate glass. The mirror structure has been optimized using the advanced Finite Element Analysis Modeling. It has very short thermal equilibrium time even without fan.

Optical Aperture (Diameter): 20.00"

S/N: 11-12-20-20K

Coating: The standard aluminum coating, 88% reflectivity

The special upgrade offer for the coating upgrades:

92% semi-enhacned coating: $130

96% semi-enhacned coating: $200

If you would like to have these upgrades, please inform us right after winning the bid.

Radius of Curvature (ROC): 165.53

Focal Length: 82.77"

PV (wavefront): 1/12.1

RMS: 1/43.3

Strehl Ratio: 0.98

Weight: ~16.8kg

Total Thickness: ~48mm

For international bidders, please make sure to use the Shipping costs tool to estimate the shipping cost before you place bid! Please also provide your phone number during check out. Both UPS and USPS require the phone number for the international shipping.

You may have to pay Custom fees, import duties, and VAT  to receive the package.

To ensure you have the most appropriate information regarding VAT rate in the EU, please read the following link:

http://pages.ebay.com/help/account/vat-main-selling-country.html

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

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 primarily because the much more efficient honeycomb structure is used in the Palomar telescope mirror.

 

2: 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:

A = d + (D-d)L / F

A=diameter of the minor axis of the secondary
F=focal length of the primary
d=fully illuminated fields desired
D=Diameter of the primary
L=distance from the secondary to focal plane

 

Normally, a secondary with 4.0" minor axis diameter is recommended for this mirror.

3: What kind of mirror cell is recommended?

A 18-point mirror cell with the sling lateral support is recommended for 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. ......


Tom Dobbins
Contributing Editor, Sky & Telescope magazine (quoted by permission)

 

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.

Star testing showed even images that were very nearly the same inside and outside of focus. Using my EZ tester (ronchi eyepiece) showed nice straight lines and no hint of TDE.

As far as I can tell this mirror is a winner and will suit my needs very well. Whether or not it actually meets the specs listed on the box I can’t tell without getting it tested. But its a lot better than the other Ebay mirrors and I like it. I wouldn’t be afraid to buy another Hubbleoptics mirror...

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 900 great reviews!)

Positive feedback rating

Nice views with this mirror. Star tests are very good.

Positive feedback rating

One word: amazing. Amazing packaging, amazing service, amazing product. Amazing.

Positive feedback rating

alles bestens, sehr schnell geliefert

Positive feedback rating

Great! the mirror is wonderful. Thank you again!

Positive feedback rating

My Truss Dobson is ready tonight the first Light, Optic ist wonderfull

Positive feedback rating

fast service, good foucault images and rhonchigram, great deal!

Positive feedback rating

Great mirror, better than expected, wunderbar, AAA+++

Positive feedback rating

Verry good quatity.Great star test results. Will purchace from this seller again

Positive feedback rating

Thanks. Tripple packed! Even UPS can't break that..

Positive feedback rating

Bien reçu ! SUPER EMBALLAGE ! Merci, à bientôt

Positive feedback rating

Nice looking mirror. This is the second transction in a week. That says it all

Positive feedback rating

Installed and saw Jupiter beautifully! Packaging EXCELLENT. A++

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.

Filed under: Eyepieces & Accessories