What to buy to replace my 8" Dob?

[eclenic]

Hi all, thanks in advance for your help!

I've owned a Skywatcher 200p Dobsonian for the past few years, and got some really nice views out of it. But overall I've never really got along with it, it's simply too big/heavy/awkward for me to comfortably move around and as such has spent most of its life in the garage instead of observing! I'm getting back into the hobby lately and am looking for something I can replace it with, but I'm having trouble deciding what to go with. 

Requirements

• Mainly visual observing, with the plan to do some casual AP
• Good views of both planets and DSOs
• Reasonably easy to move and carry, ideally in one piece
• GOTO/tracking is essential
• Don't mind buying the OTA and mount separately if necessary
• For the amount of money I know I'm going to need to spend on a setup like this, I'd like better views than I can currently get through my Dob

I've been looking at a variety of options - I was initially just considering another Newtonian on an EQ mount, but I have weight and practicality issues with that setup. So I think I'm looking at probably something like either an 8" (or bigger) SCT or a 6" Maksutov, but I don't have a great feel for these in terms of what aperture sizes are comparable, the kind of views possible, or if there's something else I should be considering entirely, like a refractor. I'm just a little lost.

Any advice for me would be great!

[johninderby]

Perhaps a 6” or 8” Claasical Cassegrain.🤔

https://www.firstlightoptics.com/search/for/classical+cassegrai

The 6” would be fine on an EQ5 or or AZ EQ5 but the 8” would need a heavier mount which would make it less portable. The advantage of the Classical Cassegrain over an mak or SCT is no corrector plate so no dewing problems and quick cooldown and use a proper crayford focuser. 

The GOTO mount is going to be the problem with a larger scope as the mount will be heavy and more awkward to carry than a dob.Something to consider.

I have both the 6” and 8” CCs on alt az manual mounts and love both of them. Great optics in both.

Edited January 3, 2021 by johninderby

[jonathan]

I think if you didn't enjoy lugging the 8" dob about then you won't enjoy lugging an HEQ5 Pro about either, nor a 9.25 or 11" SCT (which would probably need an NEQ6 Pro or similar - a VERY heavy and surprisingly bulky mount - feels like a World's Strongest Man event lifting it out to the garden in several stages).

I have an 8" SCT which I mount on an NEQ6 Pro, it would probably be OK on an HEQ5 Pro but I have to say on the NEQ6 Pro it's massively steady even in considerable wind, which is a bonus when standing on a breezy hillside.

On the SCT side of things you'll get a narrower, more magnified field of view when compared to a newtonian, which is nice for planets and small bright targets like that, perhaps not the best for dimmer objects or wide field stuff.

You could look at a 102 or 120 refractor, the mounting requirements will be considerably less than a reflector or SCT, and if it's a high quality one then you should be able to use high quality eyepieces for high magnification.

Have you considered adding castors and fold-down clamps / stands for the dob base?  I think that would be a much easier solution than spending £££ on an even heavier EQ mount.

Edited January 3, 2021 by jonathan

[Cosmic Geoff]

First, even 'casual AP' is going to require more expensive and different kit than if you stick to visual.  You can do planetary imaging with a visual outfit by attaching a planetary video camera, but deep sky imaging with long exposures really requires totally different (and expensive) kit + hours of post-processing.

If you stick to visual you could get a C8 SE, which is a fine instrument for general and planetary viewing, with a lightweignt mount. You can pick up the whole outfit and carry it outdoors.  For more money, you can get the same OTA on more sophisticated mounts (Evolution, AVX and CPC) The CPC800 is great for general viewing and planetary imaging, but is heavy. 

You could get the Skywatcher 180mm Mak, but this is heavy, best suited for planetary viewing and imaging, and will require a substantial mount.

Things to avoid IMHO: trying to do deep sky imaging with a SCT - for advanced imagers only.  Putting a SCT + fork mount on a wedge - get a proper German equatorial mount instead.

A note in passing on GoTo systems: if your interest is primarily visual IMHO you will find a Nexstar alt-azimuth GoTo much simpler to set up than a Synscan equatorial GoTo.  No polar alignment, and more user-friendly software.

[M40]

Hello eclenic and welcome to the forum. I changed from the 200P for much the same reasons as you in that each time I moved it, I was getting more concerned about dropping it. I moved to the skymax180 on an HEQ5 mount. I keep and move this in basically three elements, the mount and tripod, the OTA and the weights. I would not attempt to move it as a complete item. It is also quite a learning curve going from the DOB to a goto type mount, you have to level the thing and learn about stuff like polar alignment 🤔. Keeping it in your garage is a big plus as the OTA is already outside you are not too concerned about temperature, so once you get into it, probably from start to looking through the eyepiece is about 30 minutes, that's my record anyway 🤣 . I am with you on the tracking, with the DOB you realise just how fast everything moves so the tracking from my point of view made the costs of the upgrade well worth it. As far as better views go, can I suggest that you use the first light optics FOV tool. Pick an object you would like to observe or have observed through the 200P using an eyepiece you already have, then pick an alternative telescope using the same eyepiece to see how they compare. 

Going again, I must admit that I would look closely at the stellalyra on an eq mount. I like the idea of the fixed primary mirror, but I also like the fact that the sealed optics of the SCT/MAK reduces concerns about dust and dew. 

HTH

[Anne S]

I used to have a 8SE which was eventually moved onto a 2nd hand CG5 mount. It worked fine on that, much better than on the SE mount. You don't need to polar align for visual, just set it up with the axis pointing north using a compass. Once you've done the star alignment that will ensure the goto gets very close to each target. If you did need a more accurate polar alignment later, the Celestron and Skywatcher mounts have a polar alignment routing which consists of doing gotos to 2 different stars and then the mount moves to where the second star would be and you have to use the slow motion controls to centre it in the eyepiece. Then redo the star alignment. Not really difficult.

Celestron have replaced the CG5 mount with, I think, the AVX mount. Equivalent to a EQ5 with more objects in the handset to find, 42000, I think.  Setting up is as the previous post.

[Avocette]

Where angels fear to.......

I think you should hang on to the 200p Dobsonian until you are sure that whatever you choose to replace it with really is as good and as easy to handle! Your Dob has the significant advantage that it is very quick to settle to thermal equilibrium although it is a bit bulky and awkward. But everything is relative!

As my ‘signature’ shows I presently have a number of telescopes of various types. Not listed are the ones that I have bought and subsequently sold over the last ten years beginning with a 200p Dob, then a 250p Dob and ultimately a 300p Flextube Dob. Also the mounts I have owned and sold include a EQ3 equipped with motors and a EQ5 Pro GoTo. 

I live in Switzerland in a semi-urban semi-rural place with Bortle 5 skies (according to Clearoutside.com). However, in reality I have four yellow streetlamps which shine into the garden, so maintaining dark adaption of my eyes is almost impossible. Combining this with the physical struggle to carry my 300p Dob from its basement storage position into the garden, finally ‘clicked’ with me 18 months ago and I sold it to a much younger enthusiast. During the lockdown and continuing pandemic, my wife has been very tolerant and encouraged me to keep my favoured astro equipment in a corner of the lounge ready to carry out into the garden whenever clear skies are forecast. So I now mostly use my refractor on the GoTo mount, controlled by open source software on a Raspberry Pi (like the ASIair but DIY) and I mix a bit of EAA (Electronically Assisted Astronomy) at the time of observation with storing the captured images for later processing, more like Astrophotography. So an astro-camera has replaced my eye at the eyepiece, and I observe and control on an iPad or laptop at the telescope in reasonable weather or indoors when it’s colder. I keep the stored images for later examination and processing on cloudy nights.

During the Mars opposition and Jupiter and Saturn sessions earlier in the year, I mounted my SkyMax 150 on the EQ/AZ5 GoTo. I have to say that this combination really was at my weight limit for ‘grab & go’. The instant images were initially disappointing due to the turbulence in the atmosphere and the thermal currents inside the Maksutov, but two minute video captures provided good material for subsequent processing to tease out the detail.

Final word on ‘GoTo’. If you have a fixed mount (such as on a pier) and therefore precise alignment, then GoTo can be pretty accurate for visual observing. But with grab and go, levelling the mount and polar aligning with a conventional polarscope on an EQ mount can be tedious and back breaking. However, with an astro camera connected to some open source software, polar alignment and platesolving compensate for any small alignment errors, and GoTo really is GoTo! In the case of my SkyMax, I use a guidescope and camera to carry out the polar alignment and the GoTo functions to find the target although afterwards the mount simply tracks without auto guiding corrections.

Edited January 3, 2021 by Avocette

[bingevader]

I'd keep the dob and buy something smaller.

As people have said, an equivalent setup probably won't be much lighter.

A smaller setup would be one you could use more often with the dob for the "dob" nights.

I suppose that this is how I function at the moment.

Life, family and work mean that I don't get out as often as I'd like to.

However, some nights I just go out and look up, some I take out the binos, some I use the etx90, but then if I go out and it looks like a "dob" night, then I get out the dob!

[eclenic]

Thanks all for the replies! I'm 100% set on getting rid of the Dob at this point, but this gives me plenty to think about  At the moment I am leaning towards the SCT on an EQ mount, but the CC is a very interesting option as well! Then to decide on a size... 

[John]

The only 8 inch scope that I can think of that is as portable as an 8 inch dob would be the Celestron 8SE SCT. When I moved from an 8 inch SCT to an 8 inch dob I found the dob provided at least as good if not better performance for visual observing both deep sky and solar system targets. Plus it cooled more quickly as well and the set up was basically plonk it down and start to look though it. I've never aspired to image though so that was not a factor.

 

[johninderby]

The quick cooldown and lack of dewing problems  is a big draw for me with the Classical Cassegrains. Plus having a proper focuser. 👍🏻

Here’s my two. The CC8” is on a Rowan AZ100 mount but will be adding the GOTO option to it when it’s released later this year although do enjoy the simplicity of a manual Alt-Az mount.🙂

The CC6” is on a Manfrotto 405 geared head an Berlebach Report tripod and is my grab’n’go setup as it is easy to carry outside fully set-up using the carry handle on the scope. 🙂

And a shot of both to give a size comparison. Have upgraded both with Baader Steeltrack focusers although the stock crayfords that they come with are OK.

Edited January 3, 2021 by johninderby

[jonathan]

1 hour ago, johninderby said:

The quick cooldown and lack of dewing problems  is a big draw for me with the Classical Cassegrains. Plus having a proper focuser. 👍🏻

...

And a shot of both to give a size comparison. Have upgraded both with Baader Steeltrack focusers although the stock crayfords that they come with are OK.

 

I like the look of those shiny counterweights.

I upgraded my 8SE with a Steeltrack focuser, best upgrade by far for that scope, however it means one also has to upgrade to an EQ mount as there isn't enough room for the Steeltrack and the scope no longer balances in the old SE goto mount (which has flimsy legs anyway, and a wobbly single arm, and mine had a dodgy power socket).

So yes, 8SE is a nice size to handle but it requires a decent mount.  It's possible to carry it fully assembled on the original SE mount but after upgrading or adding anything to the scope (e.g. camera) the SE mount becomes overloaded and a bit useless.

 

[johninderby]

The SE 6/8 mount was originaly designed for the 5” SCT. Had one of the original Nexstar 5i scopes and the mount was really solid with the 5” OTA.

Edited January 3, 2021 by johninderby

[KP82]

If you're looking for better views than your current 8" dob, I'm afraid you won't be able to find anything that is more portable. 

A lot of the people have suggested a 6" SCT or Mak, but I'm going to point you to something different, SW Evostar 120ED. It doesn't have the same capability of light grasp as the dob, but it offers both unobstructed high contrast views and portability. It can also be used for astrophotography should you wish to try that in the near future. As for the mount, EQ5 will be sufficient for visual whereas HEQ5 will be the minimum if you want to do imaging.

[michael.h.f.wilkinson]

My Celestron GP-C8 has been with me for over 25 years and is wonderfully portable

Much more compact than a Dobson, but with the same aperture.

[John]

How is that much more compact overall than an 8 inch dob Michael ?

I've owned both and I don't recall that the EQ mounted SCT was more compact overall

These are all 8 inchers. The SCT is on an alt-az rather than an EQ though. The SCT OTA is shorter but the footprint wider and the overall weight a touch more I think.

All very good scopes though. Maybe it's just down to personal preferences and if the OP want's a change, it's good to have one

 

[jonathan]

2 hours ago, KP82 said:

If you're looking for better views than your current 8" dob, I'm afraid you won't be able to find anything that is more portable. 

A lot of the people have suggested a 6" SCT or Mak, but I'm going to point you to something different, SW Evostar 120ED. It doesn't have the same capability of light grasp as the dob, but it offers both unobstructed high contrast views and portability. It can also be used for astrophotography should you wish to try that in the near future. As for the mount, EQ5 will be sufficient for visual whereas HEQ5 will be the minimum if you want to do imaging.

I think that's the thing, of all the differing designs there's no getting away from size and performance, there's no magic scope that's small yet allows fantastic magnification and clarity (compared to a much larger one).  Maybe there will be in Star Trek, just not right now.  There's always going to be compromise.  I think the OP would do well to look at the refractor option, watch a lot of YouTube videos and imagine how they would handle such a telescope setup in their environment.  Spending more on higher quality glass counts for a lot when it comes to refractors.

[SiriusB]

Hello Johnathan,

                            I find SGL members always keen to help, but from your list you've set a seemingly impossible task!??

Some points for consideration:

1) I doubt you'll find 'better' views than your existing telescope in a more portable setup. It really is best bang for your buck in performance to price stakes.

2) If you want to do AP, (bearing in mind i don't @ present) realistically eq5 for an entry point? Bought one this year for visual use & quite frankly it's going to be as much a pain to carry outside as a 200p.

I can just move it about the garden with a evostar 120/150 installed, but needs breaking down to bring in/out.

So some serious 'man-up' juice required or a bit of a rethink? 😄😄

3) For visual use, a small to medium refractor on alt-az stand suits many people~quick set up etc.

4)goto,imaging & ease of transportation~tricky.

5)Keep your dob, buy a smaller Refractor or Mak as a complement. If you're dead set on imaging @ a future date maybe an 80ED would be best?

 

Sorry if that's not what you wanted to hear, Might be some better advice along later.😉

[eclenic]

2 hours ago, SiriusB said:

Hello Johnathan,

                            I find SGL members always keen to help, but from your list you've set a seemingly impossible task!??

Some points for consideration:

1) I doubt you'll find 'better' views than your existing telescope in a more portable setup. It really is best bang for your buck in performance to price stakes.

2) If you want to do AP, (bearing in mind i don't @ present) realistically eq5 for an entry point? Bought one this year for visual use & quite frankly it's going to be as much a pain to carry outside as a 200p.

I can just move it about the garden with a evostar 120/150 installed, but needs breaking down to bring in/out.

So some serious 'man-up' juice required or a bit of a rethink? 😄😄

3) For visual use, a small to medium refractor on alt-az stand suits many people~quick set up etc.

4)goto,imaging & ease of transportation~tricky.

5)Keep your dob, buy a smaller Refractor or Mak as a complement. If you're dead set on imaging @ a future date maybe an 80ED would be best?

 

Sorry if that's not what you wanted to hear, Might be some better advice along later.😉

Alas, I’m quite a small woman with a bad back so no ‘man-up juice’, as you put it, to be had. The Dob on its base weighs about 25kg and is the size and shape of a water heater, I can just barely lift it and move it about by myself. A Nexstar 8SE by contrast appears to weigh slightly more than half that weight fully assembled? If it’s bulky but light, or heavy but not bulky, I’ll be fine, it’s the combination that’s kept my scope in the garage for all this time. The AP is something I’m more looking to try and see if I enjoy it before investing in proper kit for it. Better views is obviously relative, what I really mean by that is I don’t want worse visual performance for the kind of money I’m willing to put down - so I’m not really interested in anything below a 6” aperture, and ideally I’d like to stay at at least 8”. 
 

The forum has given me plenty to chew on at least going forward though!

[dweller25]

Hello @eclenic

Do you disconnect the Skyliner OTA from the base and move the scope in two parts to keep the weight down ?

Orion Optics make an 8” Dobsonian that is much lighter than the Skyliner 200P. Quite expensive though.

I have just gone through the same process you are considering - also due to a bad back.

I now have a very light C6 - around 3.7kgs, which is a joy to use, very sharp optics and reasonably quick to cool down. I use it on a Vixen GP - it is VERY stable, but a clone like the Celestron CG5 or Skywatcher EQ5 would be fine too or perhaps a much lighter alt-az mount for visual only ?

The views are not that different compared to the Skyliner 200P, but as it’s easy to use it gets much more use - I also find the C6 observing position allows me to sit whilst observing which is very comfortable.

Perhaps you are going to have to compromise ?

Good luck and clear skies.

 

Edited January 4, 2021 by dweller25

[jonathan]

5 hours ago, eclenic said:

Alas, I’m quite a small woman with a bad back so no ‘man-up juice’, as you put it, to be had. The Dob on its base weighs about 25kg and is the size and shape of a water heater, I can just barely lift it and move it about by myself. A Nexstar 8SE by contrast appears to weigh slightly more than half that weight fully assembled? If it’s bulky but light, or heavy but not bulky, I’ll be fine, it’s the combination that’s kept my scope in the garage for all this time. The AP is something I’m more looking to try and see if I enjoy it before investing in proper kit for it. Better views is obviously relative, what I really mean by that is I don’t want worse visual performance for the kind of money I’m willing to put down - so I’m not really interested in anything below a 6” aperture, and ideally I’d like to stay at at least 8”. 
 

The forum has given me plenty to chew on at least going forward though!

Knowing what I know now, I would not buy an 8SE with a view to using it as-is, I would either look to buy the 6SE (which comes on the same mount as 8SE, so is much more stable and suffers less from vibrations) or ditch the SE mount and buy an HEQ5 Pro or AZ5 equivalent, that is the minimum mount an 8SE will reasonably perform well on IMO.  If you might struggle with an HEQ5 then an AZ5 might present the same kind of problem (assuming it's just the mount we're talking about, not mount+OTA).  Just FYI I believe it's the 4SE that comes with a flip mirror back which is handy if you want to attach a camera as well as an eyepiece.

Personally I'd recommend that you look at a 102 or 120 refractor, perhaps the EvoStar 120 on EQ3 Pro which looks like a nice portable setup, or maybe a mount + OTA combo of EQM-35 Pro with an Altair Astro 102 Wave Refractor.  Either of these should be great for visual, the Altair Astro is a higher quality product from what I can tell (I have no experience of the EvoStar line) and should provide superb visual and photography opportunities.  A refractor should afford you sharper views of stars than an SCT as there is no central obstruction and far less internal light bouncing, from my experience of both the 8SE and 102 refractor, the views are actually quite similar when it comes to detail - the image is larger in the 8SE but the 102 has greater definition and contrast so it's swings and roundabouts, sometimes I prefer the 8SE, other times the 102, but the 8SE is much more of a chore to get out and use so the 102 tends to get more use.

[Cosmic Geoff]

7 hours ago, eclenic said:

Alas, I’m quite a small woman with a bad back so no ‘man-up juice’, as you put it, to be had. The Dob on its base weighs about 25kg and is the size and shape of a water heater, I can just barely lift it and move it about by myself. A Nexstar 8SE by contrast appears to weigh slightly more than half that weight fully assembled? If it’s bulky but light, or heavy but not bulky, I’ll be fine, it’s the combination that’s kept my scope in the garage for all this time. The AP is something I’m more looking to try and see if I enjoy it before investing in proper kit for it. Better views is obviously relative, what I really mean by that is I don’t want worse visual performance for the kind of money I’m willing to put down - so I’m not really interested in anything below a 6” aperture, and ideally I’d like to stay at at least 8”. 

My C8 actually performed better optically than the 203mm Newtonian it replaced. (That newtonian was mounted on a manual EQ-5 and the combination was horrible to use).  I'm a pensioner, and I can pick up the whole C8 SE assembly without too much effort. Alternatively, you can move the OTA/mount assembly separate from the tripod.  While the SE mount is not great, it is lightweight,  adequate for visual use and does not require any polar alignment.  The Nexstar operating system is fairly user-friendly and easy to use once learnt. If you want to try AP you will need totally different kit anyway - maybe a camera directly attached to a small EQ mount.  I suspect that you would find a HEQ-5 or EQ-6 imaging mount far too heavy.

[bingevader]

13 hours ago, eclenic said:

Alas, I’m quite a small woman with a bad back so no ‘man-up juice’, as you put it, to be had. The Dob on its base weighs about 25kg and is the size and shape of a water heater, I can just barely lift it and move it about by myself.

WOW! No 'man-up juice' required! I'm not a small man and I very rarely lift my 8" dob and base in one piece.

Wheels maybe? I'm looking to add some to mine, but haven't quite found what I am looking for yet.

Edited January 4, 2021 by bingevader

[Tiny Clanger]

14 hours ago, eclenic said:

Alas, I’m quite a small woman with a bad back so no ‘man-up juice’, as you put it, to be had. The Dob on its base weighs about 25kg and is the size and shape of a water heater, I can just barely lift it and move it about by myself. A Nexstar 8SE by contrast appears to weigh slightly more than half that weight fully assembled? If it’s bulky but light, or heavy but not bulky, I’ll be fine, it’s the combination that’s kept my scope in the garage for all this time. The AP is something I’m more looking to try and see if I enjoy it before investing in proper kit for it. Better views is obviously relative, what I really mean by that is I don’t want worse visual performance for the kind of money I’m willing to put down - so I’m not really interested in anything below a 6” aperture, and ideally I’d like to stay at at least 8”. 
 

The forum has given me plenty to chew on at least going forward though!

Oh dear, I apologize for the rather antediluvian assumptions by some : as a female with a black belt in aikido I've occasionally dished out some corrective illustrations of preconceptions myself ...

I'm not qualified to suggest alternative 'scopes for you, but appreciate (from all that practice throwing humans heavier than me around ) that a small heavy 'scope you can lift and hold close to your centre of gravity will be easier to handle than a bigger awkwardly shaped one, particularly given your back problems.

Personally, I think in your situation, if there are no steps between storage location and viewing spot, I'd certainly investigate the idea of a base on wheels.

Heather

[SMF]

On 04/01/2021 at 16:48, bingevader said:

WOW! No 'man-up juice' required! I'm not a small man and I very rarely lift my 8" dob and base in one piece.

Wheels maybe? I'm looking to add some to mine, but haven't quite found what I am looking for yet.

Hi, can recommend these if interested:

https://www.amazon.co.uk/gp/product/B01DO27DE6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
 

I used a small off cut of 18mm ply I had left over from a job. Moves my VX12 around very easily and once locked are stable on a concrete drive. Almost useless on grass or gravel though.

Steve