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William Optics 102 triplet or 126 Doublet?

PostPosted: Fri Nov 16, 2018 7:13 pm
by AlexDean
Just about to buy a WO telescope but wondered if anyone can explain what the difference between these two would be apart from the focal lenght. The price is similar but I'm thinking the optics in the 102 triplet would be superior but I'll lose some focal length admittedly. I just want to buy once and have done with it (famous last words!) . Would there really be much difference in sharpness and colour? Thanks in advance .

Re: William Optics 102 triplet or 126 Doublet?

PostPosted: Fri Nov 16, 2018 8:38 pm
by Gfamily2
AlexDean wrote:Just about to buy a WO telescope but wondered if anyone can explain what the difference between these two would be apart from the focal lenght. The price is similar but I'm thinking the optics in the 102 triplet would be superior but I'll lose some focal length admittedly. I just want to buy once and have done with it (famous last words!) . Would there really be much difference in sharpness and colour? Thanks in advance .


Hi and welcome,
Firstly a caveat, that I have no personal experience of using either of these scopes, nor have I used any refractor in your price/quality bracket. So this is all theoretical.

That said; in principle, yes, there will be some difference in colour, with the doublet being liable to show some fringing on bright objects. However, if you read reviews of scopes, a lot of people find the effect is only rarely noticeable in practice for visual use, particularly for ED telescopes (as they use glass with lower dispersal characteristics anyway).

If you were planning on using the scopes for imaging you would be more likely to notice the difference between them. However, if you use a monochrome camera with a filter wheel, you would be able to get sharp focus on each set of images, allowing you to combine them in a final colour image that is sharp across the full colour range.
Other than that, the larger aperture of the doublet will give you 20% better resolution, 50% more light gathering and nearly 40% more magnification with any eyepiece.

So, as they say - this opinion is freely given and is worth every penny!

Re: William Optics 102 triplet or 126 Doublet?

PostPosted: Fri Nov 16, 2018 11:08 pm
by The Man with the Corrugated Iron Roof
I'm more inclined to think that to get the most out of a triplet you need high quality eyepieces. However if you are even thinking about astrophotography, the triplet will be better.

Re: William Optics 102 triplet or 126 Doublet?

PostPosted: Sat Nov 17, 2018 12:36 am
by Gfamily2
The Man with the Corrugated Iron Roof wrote:I'm more inclined to think that to get the most out of a triplet you need high quality eyepieces. However if you are even thinking about astrophotography, the triplet will be better.


Visually; I'd say that the doublet would almost always win over the triplet, and given the f/ratios of both, I'd be surprised if there would be any significant 'improvement' in your viewing through any particular eyepiece, in that the 126mm would 'generally' be better than the 102mm.

Yes, AP is different, and if that was going to be a definite interest, I'd advise you to put aside a similar amount* for the mount

*'similar amount' being any value between 50% and 200% the cost of the scope.

Re: William Optics 102 triplet or 126 Doublet?

PostPosted: Thu Nov 29, 2018 10:31 pm
by The Man with the Corrugated Iron Roof
I'm in a minority of one here but there's plenty of AP that you can do with short exposures, yes, even deep sky.

You will be able to do better than this: https://www.flickr.com/photos/philippug ... 6438989044