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1 Year
$26.99
2 Year
$42.99
3 Year
$54.99
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Review Summary
2023-09-07T13:58:56
Fantastic improvement in my telescope. Crystal Clear Viewing. And a fantastic price, thank you.
DONNY E.
2023-05-23T00:00:40
A really high quality star diagonal.image quality is clear n crisp which is always the case with celestron products. And the twist lock feature is a game changer. No more tiny little thumb screw gouging my eye pieces. The twist ring holds firmly n evenly. The orange ring not only looks sharp but stands out allowing u to change eye pieces in the dark more easily.
steve s.
2023-02-24T08:37:36
decided to replace the basic mirror 1.25 diagonal that came with the C8 Edge HD. A mystery why a scope with high end optics has a basic mirror diagonal - defeats the purpose of getting an HD visual. My issue with this 'twist lock' is that it really is more of a 'screw on' where you need to turns it a lot of revolutions to get the collar tight on the eyepieces. Moreover, you REALLY have to tighten the attaching collar to the back of the OTA otherwise it is regularly loosening, especially with with 2" eyepieces. My fear is overtightening/stripping the threads to stop the diagonal from flopping around. THAT IS A CHEAP DESIGN. Is the actual mirror visual a marked improvement from the original ? - hard to say. I bounced back and forth using the original 1.25 eyepiece - no discernible improvement in light/clarity. On the fence. Best comment is "OK, not WOW".
CHRISTOPHER B.
2022-03-16T12:04:41
Perfect fit on my sct and the feel is solid. I was worried about the weight of a 2? diagonal upgrade but it?s a little lighter that some of the others. My Nexstar seems fine with it. My 1.25 eyepieces fit nicely in the adapter and my 2? eyepiece fits perfectly. Love the higher visibility orange lock collars. Overall pleased with the shipping and product.
DONALD N.
2021-11-19T01:20:12
I was very impressed with the fit and finish of this Celestron telescope diagonal. This allows 2 inch eyepieces to be used, which dramatically increases the quality of astronomical viewing. I have already recommended this necessary upgrade to fellow astronomy club members.
CAROL S.
2021-11-15T08:48:29
Love the twist-lock mechanism for holding my eyepieces and the eyepieces stay secure. No moving or sliding around using the little thumb screws, which always seem to strip out after awhile. The dielectric is a huge upgrade over a standard diagonal.
Patrick E.
2021-10-26T09:11:56
Image is much brighter and clearer than standard stock diagonal
PHILIP I.
2021-09-26T09:05:08
Excellent piece - very fine craftsmanship and makes swapping pieces very fast. And yes, you can use it with the focal reducer, as well. Don't need to listen to those that say there is no purpose for it - it actually helps get the cheap sv305 to take some ok shots.
COREY S.
2021-09-09T08:56:30
Great product
David C.
2021-09-01T08:38:39
Mirror quality great, and overall materials used high quality.
Mark W.
2021-08-25T12:23:10
very well built love the twist lock still waiting for good skys to really take for test drive
DANIEL Z.
2021-05-26T12:24:23
I bought this to replace the diagonal that was missing from a used Celestron 9.25 CPC HD scope that I bought. Wow, I am spoiled now! It is more convenient to change eyepieces now than before. It is a nice upgrade, and I'm glad I bought it.
VERONICA L.
2021-05-20T03:33:21
Upgraded my Evo 9.25 with this, making it much quicker and easier to attach eyepieces. The thumbscrews on the stock diagonal interfered with a couple of my eyepieces but this one fixes that problem. Eyepieces now feel more securely attached as well. Best money spent so far.
Kenneth L.
2021-05-13T10:24:15
Didn't get a chance to use it yet. Seems to be well made. Fits eyepieces well too.
HORACE C.
2021-03-01T08:42:29
This is an outstanding star diagonal. Great optics.
Raymond S.
2020-11-26T19:11:10
Perfect device!
KRISTINA Z.
2020-11-16T10:32:50
works great
DAN B.
2020-10-14T09:30:05
Good quality for the price.
CURTIS R.
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Browse our FAQ
Over 99%
Diffraction limited
1.25", Twist-Lock
Yes, single ring
Machined aluminum black anodized
Glare threaded and painted flat black
Yes, 1.25"
114.3mm x 50.8mm x 88.9mm (4.5" x 2" x 3.5")
7.5 oz (212.6 g)
050234935739
Nice Upgrade
By VERONICA L.
I bought this to replace the diagonal that was missing from a used Celestron 9.25 CPC HD scope that I bought. Wow, I am spoiled now! It is more convenient to change eyepieces now than before. It is a nice upgrade, and I'm glad I bought it.
Great upgrade for evolution
By Kenneth L.
Upgraded my Evo 9.25 with this, making it much quicker and easier to attach eyepieces. The thumbscrews on the stock diagonal interfered with a couple of my eyepieces but this one fixes that problem. Eyepieces now feel more securely attached as well. Best money spent so far.
Find the ultimate upgrade for your telescope with the Celestron Dielectric Star Diagonal, 2" with Twist-Lock. This premium star diagonal is designed to enhance your stargazing experience by delivering brighter, sharper images without the need for a new telescope.
This high-quality star diagonal is engineered to reflect the telescope's light path at a 90-degree angle, offering a more comfortable viewing angle. The glass is fortified with 58 layers of dielectric coatings, ensuring an over 99% reflective surface. This superior reflectivity guarantees maximum light transmission to the eyepiece, enhancing the clarity and brightness of your celestial observations.
The Celestron Dielectric Star Diagonal is compatible with both 2" and standard 1.25" eyepieces, thanks to the included stepdown adapter. This flexibility allows you to enjoy a wider field of view with larger eyepieces or use your existing 1.25" eyepieces.
The innovative twist-lock eyepiece holder not only secures your eyepieces but also ensures optimal alignment between the telescope and eyepiece. Unlike traditional thumb screws, the twist-lock mechanism won't scratch or engrave the barrel of your eyepieces, preserving their quality and longevity.
The diagonal features an integrated 2" barrel stop, protecting the mirror from potential damage by long-barreled 2" accessories. Crafted from machined black anodized aluminum, all mechanical parts of the diagonal are robust and durable. The twist-lock rings are orange anodized for easy visibility.
The interior of the Schmidt-Cassegrain adapter and 2" barrel are threaded and painted flat black to prevent glare, ensuring an uninterrupted viewing experience. This diagonal also comes with two interchangeable barrels, offering versatility in connecting to a wide range of telescopes without additional adapters.
The Celestron Dielectric Star Diagonal, 2" with Twist-Lock, stands out in terms of reflectivity and optical quality, delivering top performance with an over 99% reflective mirror and diffraction-limited optical quality. By simply replacing your existing diagonal with this premium one, you can significantly enhance the views from your telescope.
https://www.celestron.com/pages/warranty
310-328-9560