Skywatcher Dob questions

[ukskies]

Hi everyone,

I am currently scopeless and live in light polluted skies in town. I have been going around in circles trying to choose a scope that I will use regularly. I am thinking about a Takahashi refractor later in the year but funding is not in place yet and may take several months, meanwhile I thought of a second scope to compliment the refractor in the shape of a used reflector.

I'm considering purchasing a dob mainly for cost v aperture. I'm a bit daunted by the size and transportability of a larger dob and am considering a skywatcher collapsible one. This looks ideal as it will fit in the car so I can transport it to a dark sky location sometimes.

Does anyone on here have one that they use regularly and if so is it a good design or are there collimation problems with this design?

Also I would like to know what is the largest size one may consider as transportable? Finally I like the idea of tracking for higher power viewing of solar system objects and wonder what your thoughts are about the synscan.

Gary

Edited February 2, 2020 by ukskies

[NGC 1502]

Hi Gary.

For visual use it’s tough to beat a Dob for top value for money.   The SW collapsible Dobs fit into a car well but are heavier than the equal aperture solid tube version - the 8” collapsible is about the same weight as the 10” solid tube.

In my local club there are two SW collapsible Dobs, owners report they hold collimation well when collapsed then extended.  They are both the go-to versions, again I’m told they work well, much better than Meade go-to SCT & Maks. The go-to Dobs of course track.

So although I’ve never used a go-to of any description it would seem that the SW scopes are good.

As to the largest size suitable for transportation it’s tough to say what would be ok for you.  If it were myself I’d try to visit a dealer with stock you can look at and try for size and weight.  Best to be cautious and not get enthusiasm take over, remember you’ll be unloading and loading in the dark when you may be tired. Better to have something smaller that you will regularly use rather than kit that is a hassle and collects dust not starlight.

Also I’d wait and see what others say, not just me.

HTH, Ed.

 

 

[johninderby]

Up to a 10” dob is not a problem to transport in most cars. Base in the boot and tube across the back seat. 

The Skywatcher dobs have been popular for years but they do have their shortcomings. The standard focuser is rather poor and fitting a better quality dual speed focuser is very common. You will finds loads of mods to improve the movement of the scope.

You should consider the Bresser dobs. At first glance look more expensive than the Skywatcher but you do get a lot more scope for the money and they already have a great focuser. proper bearings, use tube rings to mount the OTA which means you can move the tube up or down for balance and also rotate the tube to put the focuser in just the right position. Also has a rubberised anti reflection coating on the inside instead of the Skyliners thin coat of not so black paint. Also comes with a 6 point mirror cell on the 8” and a 9 point on the 10” that better support the mirror. Just a much higher spec scope. 

Used to recommend the Skyliners until I got my hands on a Bresser. However as the Bressers have only been fairly recently introduced they are very hard to find second hand wheras there are loads of Skyliner dobs on the second hand market.

[JOC]

After a lot of SGL advice I bought an 8" collapsible Skywatcher goto 200P scope on the dob base brand new.  Having used it I'd never want a solid body Dob. and would buy the same scope again.  It's easy to store in one piece taking up about as much space as a dining chair.   Easy to transport in two pieces taking about 20 seconds to take apart and rejoin.  I drive an Estate Octavia - the tube sits across the back seat, the base lays in the boot.  It holds collimation fine as far as I can see.  The focusser is fine for a bit of everything - I added a larger knob to one side for finer control, but it isn't critical.  Unless DSO's are your 'thing' you won't need more than 8" - it isn't aperture that gives you magnification - the EP does that - it just gives you more light going in for DSO's and in the UK you won't get much joy out of more than 200-250 times mag anyway.  the collapsible nature makes the tube very easy to handle with one person.  

[johninderby]

Had a 10” Flextube GOTO but replaced the flex tube with a solid tube which is actually about 1kg lighter. 

[Louis D]

2 hours ago, JOC said:

Unless DSO's are your 'thing' you won't need more than 8" - it isn't aperture that gives you magnification - the EP does that - it just gives you more light going in for DSO's and in the UK you won't get much joy out of more than 200-250 times mag anyway.

Large Dobs with well figured mirrors not only excel at DSOs, they're terrific on planets.  In a 12" to 16" Dob, you can start to clearly see barges and festoons within the belts of Jupiter that simply don't resolve in smaller scopes.  The larger exit pupils at the same magnification as smaller scopes make for a more relaxed view since you don't have to dodge floaters in your eye.  The biggest downsides to them are weight, size, and cost.  Setup time is surprising quick with a truss tube.  When I was regularly using my 15", I could be up and running in about 10 to 15 minutes.  The weight of mine got me after a severe back injury, so there is that. 😥

[JOC]

3 minutes ago, Louis D said:

When I was regularly using my 15", I could be up and running in about 10 to 15 minutes.  The weight of mine got me after a severe back injury, so there is that. 😥

I suppose it depends on what form of truss tube you are talking about - I know some of the really big ones fold up and sort of stash in a box.  However, anyone like myself who is storing their scope within a house doorway, or three really needs something that isn't that difficult to get outside.  I've got mind behind the porch door, but even then it feels a concerted effort to lug it outside.  Size and convenience of movement, esp. if you are only an interested bystander like me, is a real issue I can get mine outside in about 15 minutes too (as all the rest of my peripheral gear is stored deeper in the house), but that is 10 minutes longer than I really want to spend most nights.  You might just as well get a decent pair of binoculars if you aren't going to use it because it turns out too much aggravation to shift it all outside.

[ukskies]

Thanks for the responses everyone , it is good to know help is at hand.

I have no problems with the thought of checking the collimation  after I had set up and once the mirror had cooled, I would consider that normal with a truss tube or collapsible dob and good practice with even a solid tube. My point about the collimation was really during use, is the lockup really solid once set up? I assume I'm going to be sometimes holding the top of the scope and dragging it to a new position, I read that you can do this with synscan and just let the motors finish the job off. I just wonder is it as reliable as a solid tube?

I did look at the Bresser and it looks great to be honest, I think I would choose that over the Skywatcher if buying new. Also if buying new Orion optics UK  VX10 with 10th wave optics isn't out of price range. Every thing I spend on now will delay the Tak purchase tho so I'm mindful of that too.

I've been offered a Pristine, so I'm told, 12" sysncan flex tube but I'm worried it might be too big. I'm going to see it in the next few days so I'll probably have a better idea after that. I had kinda decided a 10" would be ideal but I guess it's worth a look.

I'm fit and active and fairly strong but 64 soon and not getting any younger, this has also to be taken into account. I may handle a 12" now but in a few years time.....

Edited February 3, 2020 by ukskies

[Guest]

I had a 14 inch skywatcher flextube. A nice scope but for me definitely not portable. The scope itself is not too bad but the mount weighed a ton, it's awkward to carry too. I don't have a permanent observatory so when I wanted to use it I had to lug 2 heavy pieces of kit outside and in the end it put me off using it altogether. So I would say 14 inch is not portable.

In any case I'm not so sure that size matters as much as you think. I now have an 8inch skywatcher 200PDS on an equatorial goto mount and I find that easily sufficient and it's a lot lighter than the SW dob I had.

[johninderby]

There is a fairly big step up in size when going from 10” to 12”. I think of 10” as being the biggest of the small scopes and the 12” as being the smallest of the big scopes if that makes any sense. Of course to some 8” is huge so until you’ve actually seen one it’s a bit hard to visualise properly. 

My old OO 14” dob with my little old 10” Sywatcher.

Edited February 4, 2020 by johninderby

[bish]

250px is a good scope and I"ve found it easy enough to transport around. As said above it is a good all rounder.

[Owmuchonomy]

I had a 12" flex tube Synscan Dob.  It was definitely a two person effort to deal with.  The mount only just fits through a standard door.  As well as being heavy you can skin your knuckles each time you try to get it outside.  I found it best to get help.  The same applies to collimation.  It is a slow job on the primary unless there is two of you because the tube is too long to manipulate the adjusters and look through the Cheshire/EP simultaneously.  Under my skies it didn't offer anything better than my 9.25 SCT when well collimated so I sold it.  The GoTo was remarkably accurate though for such a beast.

[JonCarleton]

I bought a SkyWatcher 10" Dob with SynScan GOTO about a month ago.  It is heavy, but manageable if you take the tube off the mount.  I collimate every time I setup.  I have a laser collimater and it takes just a moment.  I keep it fully assembled on a furniture dolly and lift if off on my back deck.  The rolling and lifting, along with the extreme temperature shifts we have had lately probably account for the minimal tweek it needs each time.

Otherwise, I am fine with the scope.  It does a nice job.  I did have some issues getting all the automation going, but I think I may be pushing the envelope a bit.  It is setup now as a fully automated unit that I control and view from inside the house.  That took a bit of doing, but has nothing really to do with the scope itself.

This is a picture of the Orion Nebula I took last evening (In honor of my  being considered "Nebula" level in the forum as of this writing).  You will note I have been having a bit of trouble with crispy focus with the camera.  This is a logistics problem more than anything else.  I have to run back and forth from the kitchen back outside to the scope to make small corrections in focus.  This, because I haven't automated focus...YET.

 

Edited February 3, 2020 by JonCarleton

[ukskies]

3 hours ago, johninderby said:

There is a fairly big step up in size when going from 10” to 12”. I think of 10” as being the biggest of the small scopes and the 12” as being the smallest of the big scopes if that makes any sense. Of course to some 8” is huge so until you’ve actually seen one it’s a bit hard to visualise properly. 

My old OO 14” dob with my little old 12” Sywatcher.

Wow There's a visible difference there John!😮

The OO 14 was a longer focal length model was it?

[ukskies]

Yes I am thinking the 10" is the sweet spot. It's no good having a scope I'm not going to use because it's too much effort.

What do you think of the OO mirrors John. I remember speaking to Barry Pemberton years ago when they were in Crewe, he seemed to be on a mission for quality optics at affordable prices. I wonder how good the Orion mirrors are today with Zygo reports?

[johninderby]

9 minutes ago, ukskies said:

Wow There's a visible difference there John!😮

The OO 14 was a longer focal length model was it?

Ah just realised that’s the 10” not the 12”

[ukskies]

Just now, johninderby said:

Ah just realised that’s the 10” not the 12”

That would do it! Still, a good comparison nonetheless.

[johninderby]

4 minutes ago, ukskies said:

Yes I am thinking the 10" is the sweet spot. It's no good having a scope I'm not going to use because it's too much effort.

What do you think of the OO mirrors John. I remember speaking to Barry Pemberton years ago when they were in Crewe, he seemed to be on a mission for quality optics at affordable prices. I wonder how good the Orion mirrors are today with Zygo reports?

The 1/10pv mirrors are really good and are the ones to go for. When the seeing is good they just have more contrast and are sharper. On nights of so so seeing you probably aren’t going to notice the difference over standard mirrors though.The standard mirrors are about the same as the Bresser. 

[ukskies]

Yes I'm aware of the seeing being the limiting factor most of the time but when you do get an exceptional night it is nice to know the optics can deliver.

I'm attracted to the 10th wave optics I have to admit however I do like the synscan collapsible dob idea too.

Why is choosing a scope always a compromise with something?

It's no wonder some people have about 10 scopes

[ukskies]

Was the OO dob mount good ?

[johninderby]

8 minutes ago, ukskies said:

Was the OO dob mount good ?

Think it’s the best commercial dob mount around. Very compact and strong, works very well and made of aluminium so no problems with rot if it gets wet.

The Bresser is the second best with proper sized bearings but made with laminate covered mdf so not as durable as the OO 

The Skywatcher is the poorest of the three with a poor bearing setup that needs mods to work properly and the mdf doesn’t seem to hold up as well as the Bresser.

Edited February 3, 2020 by johninderby

[NGC 1502]

1 hour ago, johninderby said:

Think it’s the best commercial dob mount around. Very compact and strong, works very well and made of aluminium so no problems with rot if it gets wet.

The Bresser is the second best with proper sized bearings but made with laminate covered mdf so not as durable as the OO 

I too like the OO Dob mounts.  Mine work well and tracking at over 200x is fine.  But I’ve had particle board Dob mounts, and prior to assembly it’s a good idea to seal the raw edges with thin wood glue, let that dry then a second coat. After assembly the joints can be sealed with white mastic being careful to make a neat job.  These simple precautions keep out the damp and give a long life.  It wouldn’t be hard to take an existing mount apart to do the above.

Ed.

 

[John]

 I've owned dobs made by GSO 8 inch, Meade 12 inch (actually another GSO made one), Skywatcher (8 and 10 inch) and Orion Optics (10 and 12 inch). They all worked pretty well out of the box except the Meade that needed more fettling to get it satisfying to use. All dobs seem to benefit from a little tweaking here and there to get the best from them though.

The worst thing about the MDF bases is that they are heavy. My current Orion Optics 12 inch dob has a base made by a fellow SGL'er from quality plywood but to a similar pattern that Orion Optics use for their mounts. It's worked wonderfully since the day it was delivered.

 

[Marvin Jenkins]

4 hours ago, John said:

 I've owned dobs made by GSO 8 inch, Meade 12 inch (actually another GSO made one), Skywatcher (8 and 10 inch) and Orion Optics (10 and 12 inch). They all worked pretty well out of the box except the Meade that needed more fettling to get it satisfying to use. All dobs seem to benefit from a little tweaking here and there to get the best from them though.

The worst thing about the MDF bases is that they are heavy. My current Orion Optics 12 inch dob has a base made by a fellow SGL'er from quality plywood but to a similar pattern that Orion Optics use for their mounts. It's worked wonderfully since the day it was delivered.

 

Hi John, I am guessing but is that sliding counter weight on a rail at the back end?

I noticed something similar on #johninderby Skywatcher but couldn’t see it clearly.

If it is then a very neat and elegant solution. Beats hanging a small dumbbell weight off the back end which I have seen in a few pictures of the past.

Marv

[ukskies]

6 hours ago, johninderby said:

Think it’s the best commercial dob mount around. Very compact and strong, works very well and made of aluminium so no problems with rot if it gets wet.

The Bresser is the second best with proper sized bearings but made with laminate covered mdf so not as durable as the OO 

The Skywatcher is the poorest of the three with a poor bearing setup that needs mods to work properly and the mdf doesn’t seem to hold up as well as the Bresser.

Thanks John, that's good to know and is temoting me towards a 10" OO now.