Williams GT81

[pragmatist]

Has anyone had any visual observing experiences with this refractor?

Thanks,

Matt

[m.tweedy]

What do you want to know.

Bearing in mind it has been cloudy for quite a while.

[pragmatist]

Well I know it's a triplet so does this make it harder for visual than say a doublet.

[rwilkey]

Hi Matt, in theory it should be better, though I doubt you would be able to tell the difference visually between a doublet (ED refractor) and a triplet, they are more often used for astrophtography than for visual.  That's why I bought a doublet (s/h mind you) as the extra expense of a triplet did not justify the visual impact in my view.

[m.tweedy]

Truthfully nothing. The only thing will be no fringing around bright stuff. Although with my doublets megrez90 and evostar 80 there is virtually none anyway.

[Davey-T]

As above, I have 100mm doublet and 110mm triplet but visually they're very similar from my location though there have been posts on here extolling the virtues of the Tak 106 for visual but then that's another design.

Dave

[m.tweedy]

f it is purely visual then "in my opinion" if you can bear a little false colour save some money and get a doublet. If it is going to be used fort imaging and cost is not an issue then go for it.

[pragmatist]

Thanks guys, any recommendations on a good doublet within or a tad over my budget?

[pragmatist]

Also is there much difference between an 80 and 100mm for planetary viewing?

[m.tweedy]

what is your budget

[pragmatist]

Around £800-900.

[DaveS]

A bit under your budget perhaps, but 100mm

http://www.firstlightoptics.com/pro-series/skywatcher-evostar-100ed-ds-pro-outfit.html

Or this a bit over, 120mm

http://www.firstlightoptics.com/pro-series/skywatcher-evostar-120ed-ds-pro-outfit.html

[m.tweedy]

what do you want to do with it.

visual, astrophotgrapy, both.

deep sky, planetary.

[pragmatist]

Visual Michael.

[DaveS]

Also, what mount are you going to put it on?

[Davey-T]

Not so much the aperture but longer focal length will stand more magnification for planetary.

I have an old f/9 refractor that gives better views of Jupiter than the 100mm f/6

Dave

[m.tweedy]

Not so much the aperture but longer focal length will stand more magnification for planetary.

I have an old f/9 refractor that gives better views of Jupiter than the 100mm f/6

Dave

beat me to it. Why a refractor? For visual on deep sky aperture is King for planetary as Davey T said focal length. 

Would you consider a SCT like a C8 or you could get a long focal length acro refractor. Or even both pre owned on your budget.

OR

go to a local astro society. look through their scopes before deciding. Many people have come to ours with a set idea but gone away with a different view point. Saves wasting/losing money.

[m.tweedy]

Just spotted your other thread.

Now that i know you previously had a C11 scrap the C8.

Only for moon and planets.Then longer focal length refractor.

On a portamount then 80-100 Skywatcher.

Good luck with getting a megrez 90. They tend to be keepers. I know because mine is.

[rwilkey]

f it is purely visual then "in my opinion" if you can bear a little false colour save some money and get a doublet. If it is going to be used fort imaging and cost is not an issue then go for it.

Hi Michael, you get no colour fringing on a doublet, esp. at f/9.  It's a great chrystal clear view.

[rwilkey]

Hi Matt, I would go for the SW 100ED DS-Pro, superb for visual at f/9 and mount it on a Vixen Porta II or an AZ4.  I like the Porta II as it has slo-mo controls, which the AZ4 does not. 

[m.tweedy]

Hi Michael, you get no colour fringing on a doublet, esp. at f/9.  It's a great chrystal clear view.

Yep I agree on the longer focal length ones. My f6 doublet has slight fringing-mainly when either side of focus but disappears when in focus.

[m.tweedy]

Hi Matt, I would go for the SW 100ED DS-Pro, superb for visual at f/9 and mount it on a Vixen Porta II or an AZ4.  I like the Porta II as it has slo-mo controls, which the AZ4 does not. 

This must be the mutual agreement society because again I agree.

[pragmatist]

Many thanks guys fur the good advice. Will look at the suggested scopes.