William Optics SCT adapter for 2'' diagonals

William Optics SCT adapter for 2" diagonals

  (7 Reviews)
✓ 2 year warranty


4x in stock shipped 1-2 working days

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Buy a William Optics 2" Dielectric Diagonal and SCT Adaptor together and save £15.

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About this product

Model:  WOsctadapter
Part Number:  D-SCT-TA

This neat and effective adapter replaces the 2" nosepiece fitted to William Optics (and clones) 2" Diagonals to enable direct connection to SCT telescopes. 

Also compatible with the Skywatcher Equinox 66 and other telescopes that utilise the SCT thread. 

Easy to fit. Simply unscrew the diagonal's 2" nosepiece then screw in this adapter. 

Customer reviews

Average Rating (7 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
SCT 2 diagonal adapter
27 January 2023  | 

Fantastic adapter that I bought with a 2 Durabright WO diagonal. This combination allows my Nexstar 8SE to view the zenith without the diagonal hitting the mount. Just remove the existing (supplied) 1.25 visual back and screw the adapter to the scope. Then unscrew the nosepiece from the diagonal and screw the diagonal onto to the adapter. Painless! Also very well made and great quality. First class service from FLO as is the norm.

Rating (max 5):  
Excellent solution for approaching Zenith on Celestron Nexstar 8SE alt az mount AND it is sturdy, orient eyepiece chain to the right, not to the left
24 October 2022  | 

I bought this component for one reason. To have my scope slew as close to the Zenith without hitting the alt-az base on my Celestron Nexstar 8SE with a 2" William Optics Dielectric diagonal. For that purpose, this component works brilliantly, with its low profile build. Although, my scope will still not quite clear the base of the mount, it certainly gets significantly closer to zenith than with a normal visual-back holder and diagonal.

I understand those who criticise this adapter when orienting eyepieces, the weight of the chain can unthread the diagonal causing the whole eyepiece chain to slip downwards...but this only happens if you orient your eyepiece chain to the left. Orient the eyepiece chain to the RIGHT instead and your eyepiece chain will lock into a very sturdy position. Just remember never orient the eyepiece chain to the left.

Because the adapter has a low profile, there is a narrow space for your thumb and index finger to tightening the visual-back thread. To change orientation of eyepiece chain during a session, I find it more easier to remove the eyepiece chain first leaving just the diagonal and then loosen the visual-back thread, change orientation, and re-tighten visual-back thread. This is the only drawback hassle with this adapter but it's a fair compromise due to it's short form factor. For Alt Az mounts, this would be no hassle at all as the eyepiece chain would remain exactly in the same orientation while slewing. But for Equatorial mounts, the orientation of the eyepiece chain will keep changing as the scope slews...so for EQ users, changing eyepiece orientation will be more of a hassle if taking my advice to remove the eyepiece chain each time...unless you can manage to loosen and re-tighten the visual-back thread properly without removing eyepiece chain.

The adapter screws on firmly holds my heavy 2" Orion Q70 38mm eyepiece. Also, tried it with a hefty chain that included a 2 to 1.25 inch converter, Televue Powermate, a 5 slot filter wheel and Baader Zoom eyepiece.

So I highly recommend this adapter if requiring a lower profile on your diagonal.

Rating (max 5):  
Not good product
04 May 2020  | 

I found this poor to use, as could not get tight fit (when it did hard to undo) and would not move to allow angle adjustments and made squeaking noise. Ended up getting a click lock and much better

Rating (max 5):  
No problems with quality just didnt fit diaganol
26 November 2019  | 

Had to return this not because of quality - just didn't fit my diaganol which was a "Williams Optics clone" -adaptor is 48mm whilst my diaganol is 45mm ?? - not possible to go from 48 to 45 easily - so other route taken.
Service good as usual

Rating (max 5):  
Has promise
28 August 2019  | 

I was very pleased to find this item which appears to be very well engineered and a good match for the Williams Diagonal purchased at the same time. I've only used it for a couple of sessions so far and have found it difficult to get a tight fit quickly to the back of my Meade SCT. I have found that it slips round quite easily and requires a bit more effort to ensure security. When slewing the scope you obviously need to keep adjusting this fitting to get the diagonal in the right position. I feel sure that I will get the knack and that this will improve with further use. The lock ring space between scope and diagonal is also fairly restricted which with fat fingers or gloves impedes access somewhat

Rating (max 5):  
Not Great....
31 January 2018  | 

Purchased one of these 3yrs ago,. First use I noticed the threads binding but only used it a couple of times due to ill health and work commitments. Came tonise it again recently and its completely seized. I mean seized solid somthat not even a vice and a strap wrench can shift it. FLO unable / unwilling to assist which is a shame as Age Id item doesnt equate to usability or fitness for purpose. I now have to purchase another and find something to lubricate the threads that wont migrate. Shame as I have no option other than to throw away a perfectly excellent diagonal.


We did decline to provide a free-of-charge adapter (three years is too long, even for us) but a little lube on the threads should solve the problem and replacement adapters are readily available. There was no need to throw away the diaginal.

Rating (max 5):  
SCT adapter for 2" diagonals
27 May 2015  | 

I bought this for connecting my sct to a new williams optics star diagonal. The first one which was delivered was faulty as the moving part between thread and body didnt move for adjustment of the position. The FLO team were excellent in sending out a new one asap whilst also sending me the postage for returning my fault one. Top class! An essential adapter for sct to 2" diagonal


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