Looking for a 2" diagonal for my 80mm triplet - need help

[Orion1]

Hi! Looking for a 2" diagonal for my 80mm triplet. I'm mostly into imaging but I would like to add a diagonal to my telescope.

currently looking at the TS (GSO?) 2" 99% dielectric diagonal (TSZS2D) and the William Optics 2" 99% dielectric diagonal (D-DIG2D-C-DB)

I have no idea - what do you think?

[iPeace]

Both decent. GSO is good value for money, they make good gear. I'm assuming the diagonal is for visual?

[Orion1]

Thanks. Yes, it is for visual

[iPeace]

I'd say any performance gain you'd get from more expensive options will be marginal, if at all noticeable. My current mirror diagonals are more up-market, but that's mostly for peace of mind. I had a 1.25" diagonal from TS - assumedly by GSO - it was faultless.

[Ben the Ignorant]

I have bought four GSO dielectric diagonals, the one you think of, and three of its 1.25" little brothers. All are excellent, and rigourously equal between them in sharpness and brightness; I made long and careful comparos. My friends' Sky-Watcher mirrors were also pitted against the large GSO, no difference. Then some days ago I received a new 2" dielectric (sold under several brands, but always the same with blue anodized sideplates).

I made yet another side-by-side with the large GSO and found them exactly equal except the new one absorbs a little violet to improve the views in semi-apos. Your triplet is a full-apo so your choice should be the large full-spectrum GSO, or maybe a premium Sky-Watcher Mirror. The only William mirror I compared with the others has a bit less sharpness, but it's price tag was higher.

Almost every clone of an optical accessory that's sold under the William brand suddenly becomes more expensive.

[laowhoo]

It's been 5 years but I recently checked and IStar are still available. Here in the US they were rated the best bang for the buck when we bought, and was surprised that an Arizona vendor carried them.

[Orion1]

I think I'll go with the TS/GSO although the WO looks cooler with carbon side plates (and probably better resale value). From what I've read the difference in performance is insignificant in this price category.

[Luna-tic]

Doesn't GSO sell to dealers who rebrand them? I have a TPO 2" quartz mirror diagonal, very nicely made, 99% reflectivity, and I believe maybe it's a GSO-made.

[Waldemar]

Maybe this can be of interest to you: https://www.cloudynights.com/articles/cat/user-reviews/the-baader-bbhs-sitall-silver-diagonal-r3038

They are expensive, but the differences may not be as marginal as is thought...