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Skywatcher Quattro 12S f4 Imaging Newtonian


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Skywatcher have released their new Quattro 12S f4 imaging Newtonian with 12" aperture and steel tube. 

Like other Quattro models the 12S is fitted with a Linear Power dual-speed focuser and features a parabolic primary mirror made of low thermal expansion Pyrex glass for shorter cool-down times. 

Interestingly on this, their largest Quattro telescope, Skywatcher have opted for a simple rolled steel tube with blackened interior. It doesn't have internal baffles. 

skywatcher_quattro_12s_f4.jpg

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It is the fast f4 ratio and large field of illumination that makes Quattros special, not the baffles. I mentioned it was interesting only because the pros & cons of baffles have been debated in multiple threads. I think the jury is still out :smile:

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I can't say I saw this one coming. It will be interesting to see if these sell well? I'm guessing it will only appeal to those with fairly large Obsy's and NEQ6 mounts as bare minimum.  

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It certainly is. 

This is pure speculation on my part but... If baffles are not carefully designed they can push tube currents into the light path rather than let them slide effortlessly up the tube walls and out the front. Considering the large 12" f4 mirror they might have decided a clean smooth-sided tube interior is more preferable than a baffled one. But baffles stiffen a tube so they have probably used thicker steel, for rigidity. They did the same for the Skywatcher 190MN, that has an unusually thick/heavy steel tube. 

I am only guessing :smile:

One thing is for sure, this isn't a telescope for the faint hearted! 

Steve 

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If it's anything like the GSO F4 Imaging Newtonian I have then the Skywatcher version will will make a really interesting imaging scope.

Have no doubts, this is a very large scope and is not to be taken lightly- but at 300mm F4 (1200mm FL) there is a nice range of objects to capture and the fast focal ratio is something to behold. I really would recomend investing in the best collimating devices and top quality coma correctors for these scopes to get the most from this scope (or any other F4 Newtonians for that matter).

You'll need at least an EQ6 class mount or better to mount the scope, prefferably in a permanently mounted observatory situation. From the outset I would also recomend looking at OAG options for imaging also.

Regarding the lack of baffles - all my Newts have been flocked internally which seems to do a good job with increasing contrast.

If you want to to stabilise a large tube Newt the best way is to use a longer, stronger dovetail bar than the supplied Vixen bar.  So think about budgeting for a heavy duty  Lossmandy 500mm dovetail bar to support the scope and another tie bar for the top of the tube rings.

If you are truely bonkers then the addition of  an ASA Keller 0.7x Coma Corrector will transform your F4 Newt into an F2.8 photon hoover......

M51 in just 140s at 12" F2.8

DSIR6693_1024_zps8ed6f634.jpg

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If it's anything like the GSO F4 Imaging Newtonian I have then the Skywatcher version will will make a really interesting imaging scope.

If this new Quattro is like the others in the series it will outperform the GSO. In particular it will have a better mirror-cell so be easier to collimate and will hold it's collimation for longer. 

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  • 4 weeks later...

Tempted by this......

I have an Orion Optics f3.8 AG8, which I love, but want a bit more focal length to get a slightly larger target resolution (smaller arc sec per pixel.....) without changing my camera (atik mono 4000). I do OAG and filter wheel so would need a field flattener with a decent back focus.....

Only real query, it's a steel tube, how will it keep focus? The cf tube on the Orion ag8 is mainly for thermal stability so concerned about temperature related focus drift.

It would be on an eq8 so no worries about the weight.....

Thoughts?

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Tempted by this......

I have an Orion Optics f3.8 AG8, which I love, but want a bit more focal length to get a slightly larger target resolution (smaller arc sec per pixel.....) without changing my camera (atik mono 4000). I do OAG and filter wheel so would need a field flattener with a decent back focus.....

Only real query, it's a steel tube, how will it keep focus? The cf tube on the Orion ag8 is mainly for thermal stability so concerned about temperature related focus drift.

It would be on an eq8 so no worries about the weight.....

Thoughts?

With a steel tube Newtonian you would be well advised to check the focus during the session especially in warmer weather when the temperature changes during the session are greater.

In the winter months, when you start with a cold scope (this is really an observatory only beast) then it's less of an issue. I always check focus between targets.

Interestingly the Skywatcher 12" F4 is 3kg heavier than than the GSO 12" F4 offering. The focuser looks smaller so I'm guessing the extra weight must be in thicker steel tube wall material? Maybe Skywatcher decided to beef up the tube assembly to reduce any flex issues?

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I once fed the dimensions of my GSO f/4 Newt into a ray tracing package. The diameter

of the OTA was only just (if that?) compatible with a non-vignetted widest possible field.

Ideally, needs a slightly over-sized OTA - And no extra baffles? lol. But don't quote me!  :p

A good "Video Light Bucket" for example. Almost a magnitude extra compared an 8"...   :)

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£799 ibbo, but an extra £150 ish for a coma corrector.still a shed load less than an ag12.......

Thanks should have looked myself :evil5:

Also need to do some measuring of my back focus distance of current cam oag and filter drawer/wheel

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  • 1 month later...

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