SKY-WATCHER SKYLINER 200P FLEXTUBE SYNSCAN GO-TO 200MM (8") F/6 PARABOLIC GO-TO DOBSONIAN TELESCOPE

[Jan Palmer]

I've been away from the telescope market for years, so I have much catching up to do. My background is in 6-inch 'home-built' Newtonian reflectors and refractors on wobbly mounts, back in the 1970's and 80's. Today I read a reply to a post on this website about how good the Skywatcher 200P is.

Not knowing what the 200P is, I Googled it and found the SKY-WATCHER SKYLINER 200P FLEXTUBE SYNSCAN GO-TO 200MM (8") F/6 PARABOLIC GO-TO DOBSONIAN TELESCOPE on Amazon UK. 

A Go-To Dobsonian? There were no customer reviews so I'm not sure how good this instrument really is. I thought that only fork and equatorially mounted telescopes can be driven by motors - certainly not a Dobsonian.  
 

Diameter of Primary Mirror: 200mm
Telescope Focal Length: 1200mm (f/6)
Eyepieces Supplied (1.25"): 10mm & 25mm

Apparently, this large telescope is very portable. The  collapsible FlexTube design and SynScan computerised Go-To technology is patented, so I doubt whether other telescope manufacturers will offer this kind of instrument soon. 

Celestial objects can be automatically be tracked - according to the description on Amazon, and the patented dual-encoder design allows one to manually move the telescope anytime and to anywhere without the need for realignment! Slewing is simply pushing the tube close to an object and one then allows the computer do the rest of the work. Cool...

At £800 sterling (around $1,000), I think this is a good price for what 'could be' a really good instrument. I'm not sure of the quality of the eyepieces though, but they can be replaced any time.

This instrument looks good to me, but am I being too optimistic? 

Does anyone know how good this 200P Go-To Dobsonian really is? Can it be used for astrophotography? 

[Owmuchonomy]

Well, welcome back.  I used to own the 12" version of this scope and it was excellent.  Not quite so 'portable' but it did everything it said on the tin.  Yes the GoTo is very reliable provided you take the trouble to place the Dob mount base on a level surface, then the GoTo and tracking are superb.  Personally I wouldn't buy it from Amazon but from an Astro dealer of repute.  You could use it for Astrophotography but I wouldn't recommend it.  An Alt-Az mount isn't really suitable for anything but short exposure lunar or maybe planetary shots.  You really need a quality equatorial mount for that purpose.  As a visual instrument, well collimated and under darkish skies it would come highly recommended.

[Jan Palmer]

Thanks ever so much for your welcome guidance, Chris. I now recall from years ago that long exposure photography is a bit dodgy with Alt-Az instruments. I forgot about that!

Well at least I'm now a little wiser. Still, it's amazing how technology has made observing so much easier. An 8 inch motor-driven computerized Dobsonian sounds really good to me.

Cheers!   

[ronin]

Goto dobsonians came out about 3 to 4 years ago and quickly caught on, people had a big mirror and they went to an object. Good aspect was it killed off the arguement of big dobsonian or a goto.

Being Alt/Az suggest you forget astrophotography. It is just not the right mount, and yes you will see images but it is more a case I suspect of ease and consistancy. Managing a good image 1 in 10 times is not a good return on time.

Not sure if it is the numerical difference but there seems few reports of problems on the Synscan on the dobsonians. Concerning portability it would be better to see one first - add a more specific location then UK, people can then suggest clubs. Just "portability" is relative. Tucking one under your arm and wandering off somewhere is different to a 1 in 5 chance of getting a hernia. However both will be reported as "portable".

Skywatcher mirrors seem reasonable, no reports of people getting a terrible one, equally people do not report talk of pin sharp views, their production and QA appears to be consistant.

[michael.h.f.wilkinson]

An 8" Dobson is an excellent all-round visual scope, with or without go-to. They are still quite portable, and a flex-tube design means you should be able to move it to dark locations by car readily. For much more portability I got myself an 8" SCT (Celestron C8 on Vixen Great Polaris mount). The EQ mount means I can do planetary imaging well, but for DSOs the scope is rather too slow. The extreme level of portability means I can readily take it on holidays easily. The downside is the price. Dobsons give real value for money. I myself prefer using a good finder to go-to, but tracking adds real comfort to observing sessions

[Jan Palmer]

Thanks for your thoughts about the 200P Go-To, Ronin and Michael. Much appreciated.

The more I learn about this interesting instrument, the more impressive it appears. 

I've visited the Sky-Watcher telescopes website and the people behind their products there will not sell sub-standard instruments. They are keen astronomers in the first place - well, that's the impression I get. 

I've always thought about getting a BIG reflector and in days long since gone. I had always thought that an 8 inch or a 10 inch instrument was BIG! With the Go-To feature, the 200P looks really tempting! But as Michael mentions, an 8" Celestron C8 on Vixen Great Polaris mount is more portable. Hmm... I'll go and have a look at that.

I live next door to the Peak District, so it wouldn't be a big problem finding a reasonable dark place from which to observe - when it's really clear!

[michael.h.f.wilkinson]

1 hour ago, Jan Palmer said:

Thanks for your thoughts about the 200P Go-To, Ronin and Michael. Much appreciated.

The more I learn about this interesting instrument, the more impressive it appears. 

I've visited the Sky-Watcher telescopes website and the people behind their products there will not sell sub-standard instruments. They are keen astronomers in the first place - well, that's the impression I get. 

I've always thought about getting a BIG reflector and in days long since gone. I had always thought that an 8 inch or a 10 inch instrument was BIG! With the Go-To feature, the 200P looks really tempting! But as Michael mentions, an 8" Celestron C8 on Vixen Great Polaris mount is more portable. Hmm... I'll go and have a look at that.

I live next door to the Peak District, so it wouldn't be a big problem finding a reasonable dark place from which to observe - when it's really clear!

I bought that C8 over 20 years ago, so the Great Polaris mount version is no longer available. There are others, like the AVX mount

[Jan Palmer]

Thanks for the update Michael. I bet I would have found out that your Great Polaris mount isn't around these days. Thanks for that.

[Stub Mandrel]

Don't abandon astrophotography completely!

See what has been achieved with tracking Alt-Az mounts on this thread first:

Field rotation doesn't seem to be a 'real' issue up to 30 second - 1 minute subs which are plenty for a lot of objects.

[Jan Palmer]

Thanks Neil! I've been thinking about Dobsonian Alt-Azimuth mounts and the Earth's rotation causing 'long-exposure' problems.

I think I've found that field rotation is worst around the meridian and least towards the eastern and western horizons - or is it the other way round? 

But who wants to take pictures in fuzzy, low altitude, smog-filled skies? 

It's all like a bit of give-and take I think.

I've just found this web page explaining in great detail the maths behind it all. 

http://daltonskygazer.com/alt-azimuth-mount-tracking-movement-and-field-rotation/

It all looks a bit too technical for me. Dob mounts aren't really geared for astrophotography.

[almcl]

Jan

Before you make your purchase, the International Astronomy show is coming up in a fortnight, at Stoneleigh in Warwickshire (not an enormous distance from Derbyshire).  Last year there were all types of Skywatcher and other scopes on show, big dobs, equatorial mounted newts, fork mounted Maks etc and you could spend anything from £200 to over £5k  and come away with an aperture that would have struck me as monstrous twenty or so years ago.  

 

If you can get there it might help your choice (or confuseit, of course).

[Cosmic Geoff]

This caught my eye as unpowered Dobsonians are relatively cheap. But this costs £750 to £800, and one can buy a 200p Newtonian on a EQ-5 equatorial mounting with Synscan for about the same amount.

So can somebody (preferably with experience of both) explain why one would choose one over the other? What about mount rigidity, and ease or convenience of use?

[Louis D]

On 9/28/2016 at 01:34, ronin said:

Goto dobsonians came out about 3 to 4 years ago and quickly caught on

Rick Singmaster was offering Sky Tracker goto capabilities on his Starmaster dobs 10 years ago.