GSO 2" 90-deg 99% Dielectric Mirror Diagonal for SCTs

5.0 Heavy, but very good

I got this diagonal to be able to sin: to use my C6 with my 2" 20mm 82° Meade UWA eyepiece AND my Meade F6.3 reducer. It worked and I enjoyed the view of the Pleiades (it's so much better than with the equivalent 32mm Plössl). However, because the C6 baffle tube is small this configuration likely has a little vignetting (and with a 34mm SWA there was a lot of it). This purchase made sense for me because I already had the 20mm 82°, but for most owners of a C6 SCT with reducer, a 24mm ES68 eyepiece is probably a better idea.

This review was provided courtesy of AgenaAstro.com

5.0 GSO 2" Mirror Diagonal (99% Dielectric)

Superb diagonal - meets and exceeds my intermediate level observing requirements. HIGHEST QUALITY - excellent workmanship and materials, fit and finish. WORKS SUPERBLY. Highly recommended for anyone who needs a really good 2" diagonal. MP Ballston Lake, NY

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5.0 Brass rings to secure eyepiece,

Brass rings to secure eyepiece, high quality mirror.

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5.0 Great product and great company

Great product and great company to deal with

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4.0 A very nice diagonal.

I would have given it 5 stars, but I found very the diagonal easily unscrews from the body, causing the diagonal to sag or drop with heavy eyepieces. There is no good way to get it snug other than to grasp the short extension tube and tighten it into the diagonal body. The upside is the body wil readily thread onto the 2" thread of my refractor! Otherwise, the view is magnificent when compared to the diagonal supplied with either my C8, or my C80ed.

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5.0 2" GSO Dielectric Diagonal for SCT

This is an excellent value and huge upgrade over the stock diagonal that came with the telescope. I use it on my C8 SCT. The diagonal allows the use of either 2" or 1,25" eyepieces in order to get a maximum fov. I like it a lot. I have purchased other items from Agena and have always been pleased with all aspects of their service.

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5.0 Excellent replacement for stock diagonal

Strong Construction,Easy to Use,Quality Lenses

I wanted to be able to use some of the 2" wide field eyepieces that I already have for a bigger scope with a Nexstar 6SE that I use for outreach events, but without spending a fortune on a high-end diagonal. The GSO diagonal fit the rear cell threads perfectly and its optical quality is well matched to this use. Direct coupling to the rear cell and the resulting optical path length also enables getting the maximum 1.3 degree view from this f10 SCT, which was important for being able to show students and visitors things like the full extent of the Pleiades or both of Bode's Nebulae in one view. I've been very pleased with the solid construction and the high quality finish. The optical quality appears to be at least as good as the telescope itself, as I see no significant difference between views through it and straight-through views without it. Of course, it gives a much more comfortable eye position than straight-through viewing, and its larger size puts the eyepiece further back and out from the rear cell, making it even easier for people to place their eye without bumping the OTA. On the 6SE it still clears the base of the mount if the OTA is shifted forward in the dovetail (necessary for balancing the heavier diagonal and eyepieces as well). The compression ring design hasn't scratched any eyepiece barrels. Overall this meets my goals perfectly.

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5.0 Great Diagonal

Strong Construction,Accurate,Easy to Use

Heavy

Great product, excellent finish. Threads directly into the rear baffle of your SCT (no need for visual back) thus saving on back focus. Ring pins for holding both 1.25" and 2" eyepieces works flawlessly.

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5.0 Nice product. Can also be used as a T-adaptor :)

Strong Construction

Heavy

Fit and finish is top notch!!! Tried to view M42 and the image is bright.

The SCT nose piece can be removed and to my surprise it was threaded to fit my T-ring. Now I don't have to buy an SCT T-adaptor and use this instead. I only need to find a suitable dust cap for the diagonal so that the mirror is protected once the nose piece is removed.

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5.0 Great Value! Great Views!!

Easy to Use,Strong Construction,Accurate

Excellent star diagonal... a real gem for the money! Construction is very impressive as are the views through it.

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4.0 Nice addition to you SCT arsenal.

Strong Construction,Quality Lenses

Heavy

Adds a little more bulk to my 6" SCT telescope. Probably an overkill to have a large diagonal.

However, it gives me peace of mind that the diagonal is properly screwed on to the telescope. I bought it to reduce the risk of the diagonal falling off and and breaking my eyepices.

This would probably be better for 8" or larger SCTs. But am happy having it on my 6". Makes it look more professional. Cheaper alternative to Celestron's 2" dielectric diagonal for SCTs.

This review was provided courtesy of AgenaAstro.com

5.0 Deserved Praise

Accurate,Strong Construction,Quality Lenses,Easy to Use

Heavy

I bought this to replace the standard diagonal that came with my Celestron NexStar 6SE telescope and the difference is wonderful, it made me feel as if I'd bought an upgrade package! I do not have any other diagonals to compare it to but for the money I can't imagine finding a better product to improve your night time viewing experience!

This review was provided courtesy of AgenaAstro.com

5.0 Superb Performance and Value

Compact,Easy to Use,Strong Construction

Best value for performance in 2" diagonals -- great way to move up to 2" SCT observing.

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5.0 Wonderful!

Strong Construction,Quality Lenses,Easy to Use,Accurate

None

I am extremely pleased that I can use the GSO's 2" SCT diagonal on 3 different telescopes due to its unique features: optional 2" nose piece and removable SCT/T2 adapter. Solid and very heavy, using it gives excellent image brightness and clarity. I love it...

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4.0 Great diagonal upgrade

Easy to Use,Strong Construction

Holds my Baader Zoom and DSLR securely. Gives enough clearance even at 90 degrees with my Nexstar 8SE.

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5.0 Excellent for replace original brands

Accurate,Strong Construction,Easy to Use

Great quality item, good price

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5.0 Good product, Quick shipping

Accurate,Lightweight,Quality Lenses,Easy to Use,Compact,Strong Construction

Good quality diagonal mirror at a reasonable price

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5.0 Nice Diagonal

Strong Construction,Well built quality

Very nice well built diagonal fits nicely on my nexstar 8se and you can switch from 1.25" lenses to 2" lenses with out much effort. All in all worth every cent.

This review was provided courtesy of AgenaAstro.com

5.0 GSO 2" Diagonal

Strong Construction

Optics are excellent, well constructed.

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5.0 Good Value for the price

Compact,Quality Lenses,Strong Construction

This diagonal is compact and well constructed and is on par with much more expensive diagonals.

This review was provided courtesy of AgenaAstro.com

5.0 Great Diagonal

Great optics,Strong Construction

None

This is a great diagonal. I use it with my Celestron C8 SCT. The optical quality and build are very good, and it is nice to use 2 inch eyepieces for wide views. The compression ring does not scratch my eyepieces either.

This review was provided courtesy of AgenaAstro.com

4.0 More than good enough for any scope

Strong Construction,2" adapter is solid

I originally bought one of these for my C8. I tried it with my William Optics 66mm refractor, and immediately ordered a second one. I'm not sure how any diagonal could be any better. Very solidly made, and very versatile.

This review was provided courtesy of AgenaAstro.com

5.0 GSO 2" diagonal

Strong Construction,Quality Lenses,Accurate

Replaced the 90 degree 1 1/4 on my Celestron 8SE. I wanted some 2" eyepeice options. I am pleased with the construction. Tried it out day viewing of the moon so far (cloudy tonight). Good fit on the 8SE. The SCT design provides the appropriate clearances for direct overhead viewing.

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4.0 Works for me!

Quality Lenses,Strong Construction

Heavy

I use this diagonal on a Celestron N8GPS and I found it to fit the bill quite nicely, allowing me the use of 2" eyepieces.

This review was provided courtesy of AgenaAstro.com

5.0 Incredible!

Strong Construction,Beautiful

None

I was upgrading from the Celestron stock diagonal, and had never seen a "real" diagonal, so wasn't sure what to expect, except that a very well respected and highly experienced astronomer had suggested the GSO. When I opened the box, I was totally stunned. The GSO diagonal is machined from a huge piece of solid aluminum with real heft and a beautiful finish. I just can't fault this perfect scientific instrument. It's cloudy right now, but I love this thing so much - its perfect construction and quality feel - that I just keep holding it and looking at it! If you are still using your stock diagonal, you really MUST upgrade, because even the highest quality scope is only as good as its weakest part. And based on my experience and the experiences of others, I can't imagine any better diagonal on the entire planet than this GSO. I work in a scientific research lab as Director, and I'm no stranger to making important equipment purchases. Well, take it from me: If this GSO diagonal was being sold in the commercial market instead of to private individuals, it would be well over $1,000. No kidding. So the bottom line is: 1) The GSO diagonal is unbelievable value for money and the highest imaginable quality. 2) For my next purchase, I will be checking to see if AGENA sells it, and if it does, I will not bother checking other suppliers. I'm ecstatic about this experience!

This review was provided courtesy of AgenaAstro.com

5.0 Bang for the buck

Strong Construction

Love the fact that I can loosen the threaded ring, rotate the diagonal, and then lock it down secure. The SCT adapter brings the diagonal in close and cuts down on the increased focal length that a 2" visual back and a refractor diagonal would otherwise provide. Though I also recieved the 2" refractor barrel and have made it a very versatile instrument. The low profile 1.25" adapter also aids in the control of increased focal length. Great product, even better price.

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5.0 High quality, low cost 2" diagonal

Quality Lenses,Strong Construction

The GSO 2" mirror diagonal has a high quality 1/12 wave mirror, and a solid feeling CNC machine body.

I've been using it for about 3 months now, and I can definitely recommend it as a 2" upgrade for anyone currently using 1.25" eyepieces.

The diagonal also includes a 1.25" to 2" low-profile adapter, which means you can continue using your smaller eyepieces and migrate gradually to the 2" optics.

For the price, this diagonal compares very well to more expensive offerings such as William Optics 2" diagonal.

This review was provided courtesy of AgenaAstro.com

5.0 Best upgrade for your SCT

Compact,Strong Construction,Accurate,Quality Lenses

I replaced my 1.25 diagonal with this 2 inch GSO.
I immediately noticed that the stars were brighter and crisper.This has been the best upgrade to my 8 inch SCT. I had to add a little more weight up front to balance the scope better.
The diagonal is solidly constructed and the mirror is flawless. I like the security of the compression rings to hold in my eyepieces

This review was provided courtesy of AgenaAstro.com

5.0 Excellent upgrade for the money

Quality Lenses,Strong Construction

I bought this as a upgrade to replace my stock diagonal on my C8. The diagonal gives plenty of room to swing my C8 for polar alignment. The optics are sharp and increases the light gathering by quite a few percent. Far superior to the Celestron diagonal. The second best upgrade to my scope. (Telrad being the 1st)

This review was provided courtesy of AgenaAstro.com

4.0 Good diagonal for the price

Quality Lenses

I have had one of these hooked up to my Nexstar 8 for about 2 years, and I can honestly say that I have never regretted getting one. I haven't had much call to check prices since then, but at the time it was by far the cheapest dielectric out there. If I had to criticize anything about it, it would be the way they have the insert for the 1.25 adapter. There is a gap cut out of the side to allow for the thumb screw of the adapter. What happens is that when you use a 2 inch EP the compression ring for the 2 inch slips around and covers this gap so that the adapter won't fit until you push the compression ring back out of the way. It isn't really a problem, but it is a little annoying.

This review was provided courtesy of AgenaAstro.com

5.0 No need for anything better!

Strong Construction,Quality Lenses

Many diagonals degrade the optical performance of an otherwise fine telescope, or have poor quality plastic parts - or both. A so-so diagonal on a superb telescope makes the scope so-so in an instant. Not so with this 2" GSO! It excels in every way, and even has brass compression rings for both 2" and 1-1/4" eyepieces so they won't get set-screwed! Would buy again without a second thought. Highest recommendation.

This review was provided courtesy of AgenaAstro.com

4.0 Plenty of Light through this Diagonal

Accurate,Great value for the money,Strong Construction

Don't be fooled by the price.. this is a quality diagonal!

This review was provided courtesy of AgenaAstro.com

4.0 Solidly built, good images

Good value,Solidly built,Better than stock diagona

None noticeable

I bought this to replace the stock 1.25" diagonal that came with my second hand Nexstar 8 GPS, and I'm happy with my purchase.

It seems to be solidly built, threads on very cleanly and I think the images are bit brighter than the stock diagonal.

I also like the fact that Agena Astroproducts sells the chrome refractor style end tube separately, and I bought that and a 2" SCT adapter at the same time so I could use it both ways (mainly for filters and threading the barlow from 20mm 80 degree Agena UWA eyepiece in before the diagonal).

Good value, especially for the price, and I love the versatility of using it with filters and the barlow element.

This review was provided courtesy of AgenaAstro.com