Thinking of buying these 200 Dobs

[PlanetGazer]

Good Afternoon to all,

Glad to be back to this community, after a period of inactivity in my best hobby.

 

I may need your thoughts and help as I'm thinking of buying one of these 200mm/8inch Dobs:

* Sky-Watcher Skyliner 200P Dobsonian ( £275 )

https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-200p-dobsonian.html

* Sky-Watcher Skyliner 200P FlexTube GOTO ( £749 )

https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-200p-flextube-goto.html

 

Both are Skywatcher 8 inch dobs, only difference is the collapsible/flex tube + the GoTo, as far as I know. The price difference is relatively huge, I understand that these two features are game changing but is it worth the difference? (roughly £90 for the added flex feature and £400 for adding a  GoTo to a telescope)

 

Personally, I'm after the flex-tube feature and couldn't find an 200 flex dob with no GoTo, which made me consider having a GoTo feature. Will the GoTo feature track an object ? as this may help me if I ever consider astro-photography.

 

On another note, is it possible to add a GoTo to a dob stand later on?

 

You help is much appreciated!

 

 

Edited June 14, 2019 by PlanetGazer

[8472]

If you eventually want to take the imaging route, you can forget the flex tube for anything serious.

Field rotation. 

[Nigella Bryant]

As far as I know you'd only get max 20secs /30secs subs b4 field rotation takes affect. If eventually AP is your goal then better to get an equatorial mount. Just a thought. 

[Vondragonnoggin]

You can do EEVA eventually with the goto. Most EEVA exposures less than 30 seconds and generally faster than that.

 

You might consider a non-goto flex-tube also. It’s a little heavier actually than the solid tube, but with it collapsed, you can stuff the tube into a tighter space in a vehicle to drive it somewhere darker to view.

The solid tube and fully extended flex-tube will keep collimation duties about the same. Collapsing the flex-tube will definitely make you need to do collimation again. I used to keep mine extended for that reason. I only had to carry it down three stairs to my back deck so it kept collimation very well, but as soon as I collapsed it and re-extended, it needed collimation for sure.

 

I traded mine a few years back but it was a great scope for many years to me. I decided to try a few different scope types. Refractors and Maks now, but really enjoyed the flex-tube dob while I had it. It was traded for a Twilight II manual alt-az mount.

[R26 oldtimer]

I would not consider a goto dob for anything smaller than 10" or 12".

There are better and more versatile mounts for scopes smaller than 12" such as the Heq5 or eq6 or the azeq equivalents. The dobsonian mount is a great concept when it comes to keep a large scope steady without having to pay as much as a car for a mount to hold  a 14"-16"-20".

So I would either go for the Skyliner 200P Dobsonian or a 12" manual dob or something like that:

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-200pds-heq5-pro.html

Edited June 14, 2019 by R26 oldtimer
typo

[vlaiv]

Goto feature is what accounts for bulk of additional cost.

It allows you to both find objects and track them. Such scope is not well suited for serious AP, but can be used for EEVA/EAA quite successfully. It can also be used for planetary imaging.

Not sure if flex version is useful for anything else except storage and transport (which is not huge issue with 8" scope anyway).

For me, goto would be useful for tracking when observing at higher magnifications - like Moon and the planets. However, for that purpose there is a cheaper solution that works almost as good (and in some respects even better) - EQ platform. It is "base" that you can put your dobsonian telescope on and it will track object for up to one hour before it needs "rewinding". It does not use continuous motion but rather tracks for certain segment of "circle" (because it is low lying platform and not full fledged EQ mount), after it reaches end of its motion, it needs to be "reset", or "rewinded" to start position (this is fairly easy to do and lasts about a minute). It is cheaper alternative even if buying it ready made, but can also be DIY project if you fancy that sort of thing - there are plenty of blueprints online for it. It suffers form one drawback - it is built for particular latitude (+/- few degrees) so it is useful for particular place but can be used on trips to local dark site.

If you after all decide to get proper EQ mount, then SW version of dob is not the best to get now. Look at Bresser 8" dob. This is because SW version has integrated parts for mounting to dob base - these are not easily removed and fitted back. Bresser dob has different solution - it uses tube rings, and it is much easier to transfer to EQ mount and back.

If you think of using such a large newtonian on EQ mount - please consider the fact that EP/focuser can end up in really strange positions and this is handled by rotating the OTA in its mounting rings. 8" newtonian can be as much as 10Kg in weight and rotating the scope in its rings is not as easy for such a large scope. If you want just to observe and/or do some planetary imaging, possibly EAA - either Goto or EQ platform is better solution.

[PlanetGazer]

2 hours ago, 8472 said:

If you eventually want to take the imaging route, you can forget the flex tube for anything serious.

Field rotation. 

2 hours ago, Nigella Bryant said:

As far as I know you'd only get max 20secs /30secs subs b4 field rotation takes affect. If eventually AP is your goal then better to get an equatorial mount. Just a thought. 

I would not consider AP seriously at the moment, and would prioritise the convenience of a dob for the time being. I have an SWatcher 130 with an EQ mount. Thanks of the replies, and can use that

 

2 hours ago, Vondragonnoggin said:

You can do EEVA eventually with the goto. Most EEVA exposures less than 30 seconds and generally faster than that.

 

You might consider a non-goto flex-tube also. It’s a little heavier actually than the solid tube, but with it collapsed, you can stuff the tube into a tighter space in a vehicle to drive it somewhere darker to view.

The solid tube and fully extended flex-tube will keep collimation duties about the same. Collapsing the flex-tube will definitely make you need to do collimation again. I used to keep mine extended for that reason. I only had to carry it down three stairs to my back deck so it kept collimation very well, but as soon as I collapsed it and re-extended, it needed collimation for sure.

 

I traded mine a few years back but it was a great scope for many years to me. I decided to try a few different scope types. Refractors and Maks now, but really enjoyed the flex-tube dob while I had it. It was traded for a Twilight II manual alt-az mount.

Great to hear that! I would have to research EEVA more

and I agree, flex would be more convenient for the car I have, but having the flex extended most of the time is not what I would I do where I live atm, dust is annoying here. May I ask why would the flex tubes bad for collimation?  collapsing the tube disrupt the mirror?

2 hours ago, R26 oldtimer said:

I would not consider a goto dob for anything smaller than 10" or 12".

There are better and more versatile mounts for scopes smaller than 12" such as the Heq5 or eq6 or the azeq equivalents. The dobsonian mount is a great concept when it comes to keep a large scope steady without having to pay as much as a car for a mount to hold  a 14"-16"-20".

So I would either go for the Skyliner 200P Dobsonian or a 12" manual dob or something like that:

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-200pds-heq5-pro.html

 I read your point, but for me personally, I wouldn't go for larger than an 8 inch for portability reasons, and having a Dob is something I have been considering for a long time.

34 minutes ago, vlaiv said:

Goto feature is what accounts for bulk of additional cost.

It allows you to both find objects and track them. Such scope is not well suited for serious AP, but can be used for EEVA/EAA quite successfully. It can also be used for planetary imaging.

Not sure if flex version is useful for anything else except storage and transport (which is not huge issue with 8" scope anyway).

For me, goto would be useful for tracking when observing at higher magnifications - like Moon and the planets. However, for that purpose there is a cheaper solution that works almost as good (and in some respects even better) - EQ platform. It is "base" that you can put your dobsonian telescope on and it will track object for up to one hour before it needs "rewinding". It does not use continuous motion but rather tracks for certain segment of "circle" (because it is low lying platform and not full fledged EQ mount), after it reaches end of its motion, it needs to be "reset", or "rewinded" to start position (this is fairly easy to do and lasts about a minute). It is cheaper alternative even if buying it ready made, but can also be DIY project if you fancy that sort of thing - there are plenty of blueprints online for it. It suffers form one drawback - it is built for particular latitude (+/- few degrees) so it is useful for particular place but can be used on trips to local dark site.

If you after all decide to get proper EQ mount, then SW version of dob is not the best to get now. Look at Bresser 8" dob. This is because SW version has integrated parts for mounting to dob base - these are not easily removed and fitted back. Bresser dob has different solution - it uses tube rings, and it is much easier to transfer to EQ mount and back.

If you think of using such a large newtonian on EQ mount - please consider the fact that EP/focuser can end up in really strange positions and this is handled by rotating the OTA in its mounting rings. 8" newtonian can be as much as 10Kg in weight and rotating the scope in its rings is not as easy for such a large scope. If you want just to observe and/or do some planetary imaging, possibly EAA - either Goto or EQ platform is better solution.

I like the idea of tube rings for Dobs! found it https://www.bresser.de/en/Brand/Bresser/BRESSER-Messier-8-Dobsonian.html 

However, as I said, I'm not looking for an EQ, I know they are much better for tracking , but as you said the GoTo can help a little bit in tracking, I guess you convinced me of the Goto feature. I'm leaning towards the  Sky-Watcher Skyliner 200P FlexTube GOTO

 

 

[Vondragonnoggin]

Astrozap makes a shroud for the flex-tube. FLO sells it too. Keep the cap on the top of the tube and the shroud on and no dust worries. Really helps with stray light in light polluted viewing locations.

 

https://www.firstlightoptics.com/dew-prevention/astrozap-light-shroud-for-skywatcher-flextube.html

[Cosmic Geoff]

I would suggest that instead of choosing a telescope because you "like" it, you decide what you want to observe (or image) and buy equipment suitable for that function.  Being prepared to spend the price of a new 8" GoTo Dob gives you some leeway.

Some tips: Look at what serious deep-space or planetary imagers actually use.

What kind of visual telescope would you really like, taking cost out of the equation? Perhaps one half the length and weight of the equivalent Newtonian, with a more convenient eyepiece position that stays near one position, and a large focal range to accommodate accessories that add length to the light path?

Not having GoTo gives you a huge bias to only observing objects that are easy to find and track.

What kind of mount? These days you only really need an equatorial for long exposure astrophotography.   Mounts bundled with 8" telescopes vary

hugely  in ease of setup, portability, weight, stiffness and embedded cost.

A 8" Newtonian atop a EQ5 or similar mount is a pig to use, whether for visual or for astrophotography.

Edited June 15, 2019 by Cosmic Geoff

[fiestazetecmk2]

200p skyliner. Easy to use and set up.great veiws. Not heavy .no electronics to go wrong .maybe the only scope you'll ever need.

[8472]

To add to all of the above, you can buy the Dob, build yourself an eq platform (which will track well enough for visual), buy a used camera tracker, used dslr and adapt an old M42 lens (all for widefield imaging) all in for roughly the price of the Flex tube.

That is exactly the way I did it and have no regrets. 

[Astro-Geek]

Lots of good advice on here already.

My thoughts are that the flextube option is no advantage with a 200p because it's quite manageable as a rigid tube and it is possible to put it in standard rings for later EQ mounting.  I agree that the Bresser is halfway there already, just needing the dovetail, but it can be done with a skywatcher 200p too.

(But it would be pretty much impossible with a flextube).

The attached photo shows my "hybrid" 200PDS with dual Dobsonian mount and Rings/Dovetail.  They do fit, both together, just.

I bought it as a 200PDS with rings but then hankered for it to also be Dob mounted for quick "mobile" sessions.  I was lucky enough to find someone selling most of a used 200p Dob base, (the uprights, bearings etc.., all except the circular turntable base, which was fairly easily fabricated from 18mm MDF and a lazy susan bearing).

I retro fitted the large plastic Dobsonian Bearings to the OTA after careful measuring, and they happily co-exist with the standard rings and dovetail.  So it can be used as a Dob or simply lifted off and fixed to my EQ6 mount for Astro or accurate tracking.

I would however suggest that it's much easier to buy  the Dob version and then just add the rings, then there's no DIY modding and it can always revert to a pure Dob.

If I ever had to restrict myself to just one telescope (perish the thought.. 🤓), it would be this one, for maximum versatility and convenience.

Edited June 15, 2019 by Astro-Geek

[Geoff Lister]

Having enjoyed the Synscan GoTo with my Skymax 127mm Mak., I decided to increase my aperture with the Skyliner 250 flex-tube, and the same Synscan control. When stowed, I cover the OTA with an old bed-sheet to keep out dust. The truss tubes extend to very positive end stops, and so the OTA keeps collimation very well. I probably make minor adjustments about every 6 months.

The GoTo and tracking are very good, used mainly for visual observing, but with the GPCAM feeding my laptop, running SharpCap and its live stacking mode, seems to compensate for minor field rotation. It gives me a decent depth of colour when viewing DSOs.

Geoff

[PlanetGazer]

14 hours ago, Cosmic Geoff said:

I would suggest that instead of choosing a telescope because you "like" it, you decide what you want to observe (or image) and buy equipment suitable for that function.  Being prepared to spend the price of a new 8" GoTo Dob gives you some leeway.

Some tips: Look at what serious deep-space or planetary imagers actually use.

What kind of visual telescope would you really like, taking cost out of the equation? Perhaps one half the length and weight of the equivalent Newtonian, with a more convenient eyepiece position that stays near one position, and a large focal range to accommodate accessories that add length to the light path?

Not having GoTo gives you a huge bias to only observing objects that are easy to find and track.

What kind of mount? These days you only really need an equatorial for long exposure astrophotography.   Mounts bundled with 8" telescopes vary

hugely  in ease of setup, portability, weight, stiffness and embedded cost.

A 8" Newtonian atop a EQ5 or similar mount is a pig to use, whether for visual or for astrophotography.

well my max budget is 750 quid, but would be nice if I can get a 200mm with third the price. I agree the GoTo 42,000 objects is amazing feature.

14 hours ago, fiestazetecmk2 said:

200p skyliner. Easy to use and set up.great veiws. Not heavy .no electronics to go wrong .maybe the only scope you'll ever need.

thank you for the feedback!

12 hours ago, 8472 said:

To add to all of the above, you can buy the Dob, build yourself an eq platform (which will track well enough for visual), buy a used camera tracker, used dslr and adapt an old M42 lens (all for widefield imaging) all in for roughly the price of the Flex tube.

That is exactly the way I did it and have no regrets. 

wow amazing, any topics on how you built your self an EQ mount for it?

 

 

[PlanetGazer]

2 hours ago, Astro-Geek said:

Lots of good advice on here already.

My thoughts are that the flextube option is no advantage with a 200p because it's quite manageable as a rigid tube and it is possible to put it in standard rings for later EQ mounting.  I agree that the Bresser is halfway there already, just needing the dovetail, but it can be done with a skywatcher 200p too.

(But it would be pretty much impossible with a flextube).

The attached photo shows my "hybrid" 200PDS with dual Dobsonian mount and Rings/Dovetail.  They do fit, both together, just.

I bought it as a 200PDS with rings but then hankered for it to also be Dob mounted for quick "mobile" sessions.  I was lucky enough to find someone selling most of a used 200p Dob base, (the uprights, bearings etc.., all except the circular turntable base, which was fairly easily fabricated from 18mm MDF and a lazy susan bearing).

I retro fitted the large plastic Dobsonian Bearings to the OTA after careful measuring, and they happily co-exist with the standard rings and dovetail.  So it can be used as a Dob or simply lifted off and fixed to my EQ6 mount for Astro or accurate tracking.

I would however suggest that it's much easier to buy  the Dob version and then just add the rings, then there's no DIY modding and it can always revert to a pure Dob.

If I ever had to restrict myself to just one telescope (perish the thought.. 🤓), it would be this one, for maximum versatility and convenience.

Sir, what you have done there is amazing!

 

After reading your reply, I'm having second thoughts about the flex tube, but still would love a GoTo, which makes me wonder why I never found an 8 solid tube dob with a GoTo, how hard is it to assemble a GoTo to dub? wonder if GoTos are sold separately anyway?!

1 hour ago, Geoff Lister said:

Having enjoyed the Synscan GoTo with my Skymax 127mm Mak., I decided to increase my aperture with the Skyliner 250 flex-tube, and the same Synscan control. When stowed, I cover the OTA with an old bed-sheet to keep out dust. The truss tubes extend to very positive end stops, and so the OTA keeps collimation very well. I probably make minor adjustments about every 6 months.

The GoTo and tracking are very good, used mainly for visual observing, but with the GPCAM feeding my laptop, running SharpCap and its live stacking mode, seems to compensate for minor field rotation. It gives me a decent depth of colour when viewing DSOs.

Geoff

Thank you all for the advise!

[Vondragonnoggin]

While considering the solid tube for dual mounting is interesting, I personally find big newts awkward for visual use on GEMs and starting AP with a 1200mm focal length newt on a GEM after doing visual with a Dobson base is a bear of a switch. The GEM needed for such a big tube will be costly.

I’m more a fan of barn door trackers and slr lenses for starting AP or a 60-80mm refractor at F/6 on a beefy enough GEM to have a capacity of over twice the weight of the 60-80mm refractor.

 

Going from manual dob to AP is drastically different. You could ease into the process with a goto dob and some EEVA activities though.

[8472]

55 minutes ago, PlanetGazer said:

wow amazing, any topics on how you built your self an EQ mount for it?

 

 

https://www.eastmidlandsstargazers.org.uk/topic/12353-my-eq-platform-project/

[Astro-Geek]

14 hours ago, PlanetGazer said:

After reading your reply, I'm having second thoughts about the flex tube, but still would love a GoTo, which makes me wonder why I never found an 8 solid tube dob with a GoTo, how hard is it to assemble a GoTo to dub? wonder if GoTos are sold separately anyway?!

Thank you all for the advise!

You're right, I always wondered why Skywatcher don't appear to have produced a solid 8 inch goto.

When I was searching, I did find an Orion one, the  N 203/1200 SkyQuest XT8 IntelliScope.

https://www.astroshop.eu/telescopes/orion-dobson-telescope-n-203-1200-skyquest-xt8-intelliscope-dob/p,33297

(apologies for not posting an Flo link, they don't seem to do Orion scopes.)

At £630 including shipping to the UK it's quite a bit cheaper than the Skywatcher 200 flextube goto, but it is a "push to" instead, which is better in some respects IMHO.  The Az and Alt sensors enable the same object finding, but you push it to the indicated angles instead of the motors doing it and there is no tracking, so it will not follow an object.

I found that Retro fitting goto to a Dobsonian is expensive and not straightforward. Each mount is quite specific with non-standard bearings.

I therefore went for a simple DIY azimuth scale on the base and  a cheapo clone of a  magnetic "wixey" electronic angle gauge.  Costing only a few pounds these are so simple to attach and use.  Once calibrated on a horizontal surface, they just attach to the OTA near the top and give a precise alt angle of whatever it's pointing at.  I then just use an android tablet (or phone) running a free stellarium type app to search for an object and then point the Dob in the expected location.  It may be less accurate than an electronic goto and there's no tracking, but it gets me within a degree or so, and the additional "brainpower" steps of transferring the angles is more satisfying somehow. 🤓

 

 

Edited June 16, 2019 by Astro-Geek

[johninderby]

You could make your own solid tube goto. I did a 250px version a few years ago by combining a Skywatcher newt OTA with a GOTO base. Makes you wonder why Skywatcher doesn’t offer this as an option. They would probably say not enough demand but I think there would be.

[PlanetGazer]

7 hours ago, Astro-Geek said:

You're right, I always wondered why Skywatcher don't appear to have produced a solid 8 inch goto.

When I was searching, I did find an Orion one, the  N 203/1200 SkyQuest XT8 IntelliScope.

https://www.astroshop.eu/telescopes/orion-dobson-telescope-n-203-1200-skyquest-xt8-intelliscope-dob/p,33297

(apologies for not posting an Alo link, they don't seem to do Orion scopes.)

At £630 including shipping to the UK it's quite a bit cheaper than the Skywatcher 200 flextube goto, but it is a "push to" instead, which is better in some respects IMHO.  The Az and Alt sensors enable the same object finding, but you push it to the indicated angles instead of the motors doing it and there is no tracking, so it will not follow an object.

I found that Retro fitting goto to a Dobsonian is expensive and not straightforward. Each mount is quite specific with non-standard bearings.

I therefore went for a simple DIY azimuth scale on the base and  a cheapo clone of a  magnetic "wixey" electronic angle gauge.  Costing only a few pounds these are so simple to attach and use.  Once calibrated on a horizontal surface, they just attach to the OTA near the top and give a precise alt angle of whatever it's pointing at.  I then just use an android tablet (or phone) running a free stellarium type app to search for an object and then point the Dob in the expected location.  It may be less accurate than an electronic goto and there's no tracking, but it gets me within a degree or so, and the additional "brainpower" steps of transferring the angles is more satisfying somehow. 🤓

 

 

Further to what you have posted, I also found a goto one, but it's very expensive !

 

 https://www.amazon.com/Orion-10134-Computerized-Dobsonian-Telescope/dp/B003E8K53C

6 hours ago, johninderby said:

You could make your own solid tube goto. I did a 250px version a few years ago by combining a Skywatcher newt OTA with a GOTO base. Makes you wonder why Skywatcher doesn’t offer this as an option. They would probably say not enough demand but I think there would be.

Did you buy the stand separately?  Or did it came with another telescope?

Edited June 16, 2019 by PlanetGazer

[johninderby]

It was originally a flex tube but I sold the flex tube OTA and bought  the solid newt OTA . Used a pair of the regular dob mounting parts and drilled mounting holes in the tube. 

[awlfc]

I've just bought the 200p skywatcher Dob solid tube. I thought about getting the Felx Tube but couldn't see the point in spending out the huge amount extra. I have bought a 2 extra eyepieces and a Barlow with the money saved and I'm still quids in. 

[JOC]

On 16/06/2019 at 08:36, johninderby said:

You could make your own solid tube goto.

As I have often posted I wonder if it's a weight issue - is the flex-tube lighter - my own 200P flex-tube motors seem VERY susceptible to weight distribution.   However, when it all works it's brilliant. 

19 hours ago, awlfc said:

I've just bought the 200p skywatcher Dob solid tube. I thought about getting the Felx Tube but couldn't see the point in spending out the huge amount extra. I have bought a 2 extra eyepieces and a Barlow with the money saved and I'm still quids in. 

It's to be hoped you end up better at finding things in the night than I am then.  I've found things with my 200P goto that I would never have found without it.  

FWIW I had the same decision to make as the OP - I went with the Flex-tube goto 200P and never by any stretch of the imagination regretted it.  If you don't want to take the time calibrating it each time then it can also be used for quick looks at easy to find things as a manual scope too.

[johninderby]

The flex tube OTA is actually heavier than the solid tube. All the additional bits need to make the tube collaspable weigh more than just a bit of plain tube.

[PlanetGazer]

On 17/06/2019 at 15:49, johninderby said:

The flex tube OTA is actually heavier than the solid tube. All the additional bits need to make the tube collaspable weigh more than just a bit of plain tube.

I think his point of a solid tube, was to have the option of using it on an EQ mount, since  the eq mount connect to rings that hold the tube with friction.