William Optics 102 triplet or 126 Doublet?

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William Optics 102 triplet or 126 Doublet?

Postby AlexDean » Fri Nov 16, 2018 7:13 pm

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 .
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Re: William Optics 102 triplet or 126 Doublet?

Postby Gfamily2 » Fri Nov 16, 2018 8:38 pm

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!
Scopes: Meade 8" SCT, Skywatcher 127mm Mak, Raffle winner of SW ST80
For imaging: Pentax K5, Asda webcam, Star Adventurer (new toy)
For companionship: Mid Cheshire Astronomical Group.
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Re: William Optics 102 triplet or 126 Doublet?

Postby The Man with the Corrugated Iron Roof » Fri Nov 16, 2018 11:08 pm

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.
How can I be one with the universe when we don't know what 96% of it is.

About Me: https://www.amazon.com/Philip-Pugh/e/B0034NTCJK

My blog: http://sungazer127mak.blogspot.com/

Photos: https://www.flickr.com/photos/philippughastronomer/
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Location: Wiltshire but can be just about anywhere up to 41 000 feet

Re: William Optics 102 triplet or 126 Doublet?

Postby Gfamily2 » Sat Nov 17, 2018 12:36 am

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.
Scopes: Meade 8" SCT, Skywatcher 127mm Mak, Raffle winner of SW ST80
For imaging: Pentax K5, Asda webcam, Star Adventurer (new toy)
For companionship: Mid Cheshire Astronomical Group.
(Not a moderator)
Gfamily2
 
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Re: William Optics 102 triplet or 126 Doublet?

Postby The Man with the Corrugated Iron Roof » Thu Nov 29, 2018 10:31 pm

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
How can I be one with the universe when we don't know what 96% of it is.

About Me: https://www.amazon.com/Philip-Pugh/e/B0034NTCJK

My blog: http://sungazer127mak.blogspot.com/

Photos: https://www.flickr.com/photos/philippughastronomer/
The Man with the Corrugated Iron Roof
 
Posts: 501
Joined: Sat Nov 23, 2013 1:53 pm
Location: Wiltshire but can be just about anywhere up to 41 000 feet


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