Big GOTO Dobs - Skywatcher - any good? - which one?

[janoskiss]

At this stage this is just a dream but this may be something to aim and save up for: a large aperture Skywatcher GOTO/SynScan Dob.

The largest one is the 16-inch (http://astropetes.com.au/telescopes/Skywatcher_GoToDob_16.html). While that kind of aperture sounds exciting I'm thinking that since that is the largest one, it is probably pushing the limits of what mass-produced built-down-to-a-price Chinese manufacturing can do, so the the 14-inch (http://astropetes.com.au/telescopes/Skywatcher_GoToDob_14.html) might be a more sensible option and more likely to be a better performer in practice. (Thinking about mirror figuring quality, cooling times, tube and mount stability, stress on the motor drives, GOTO/tracking accuracy, durability etc.)

I'd love to hear from anyone who's got one of these scopes or has had a chance to play with one.

As I said to begin with, I'm only dreaming for now because I don't have that kind of money, but in the longer term, if these scopes are any good, I'd be glad to part with $3-4k for that sort of aperture on a Goto scope. OTOH it'd be a lot of money to throw away if the scopes are just so-so or worse; especially if the optics are not up to the task.

I don't expect the scope to be perfect out-of-the-box (they never are) and expect to have to mod it to get the most of it. But I do want optics that perform reasonably well at high powers given the right conditions -- not just cheap light buckets that are outperformed by smaller scopes on planets.

The scope would be housed and used permanently at a dark (mag 6) sky location in north-east Victoria.

Besides visual use I'd be interested in doing some imaging, especially planetary using the video capture + frame stacking method (since the scopes have GOTO and alt-az tracking).

[rustigsmed]

hi steve

well actually the biggest is the 18" but it is a carbon fibre truss skywatcher dob. way more expensive than the 16" from the regular series.
I have the 12" which i recommend definitely. the tracking / goto is spot on and the views are high quality. The mount has a different system on the 14 and 16" versions i think needing be in two parts rather than one i don't know if that has any effect on tracking.
the 12" is quite large (even as a flex tube) you'd really need a semi permanent spot for the 14"-16" versions. looking at the prices they are so much more affordable than when i got mine i think the price for 12" would sit between the 14 and 16" models now, so they really are great value.


Russ

[janoskiss]

Thanks Russ! Yeah I know about the 18 and maybe 21" (?) also coming soon but they are a big jump up in price and a different, and by the looks more refined, design. I used to own a 12" GSO Dob (just a basic push-to) but I much prefer my 10" Saxon (SW/Synta by another name) which has a much better mirror (US made, pyrex glass, or so I'm told; in any case it performs exceptionally well and it's a definite keeper). If I was to get a bigger scope (as well) 14" is probably the smallest I'd go with. 12" and 10" are too close. And it's not likely I'll get another mass-produced mirror as good as my 10".

Not sure what you mean by the mounts for the 14 and 16" being a different design from the 12". Superficially, from marketing photos, they look identical. Actually that's a bit of a concern: all models from the 8" to 16" seem to share the same Goto hardware. One would think that a 16" needs something beefier than an 8". Or maybe they are in fact beefier underneath the plastic covers...? If not and the motors are good enough to drive a 16", then one could perhaps just buy the 8" Goto dob strip out the Goto, get a 16" mirror (http://www.ebay.com/itm/16-f-5-Sandwich-Parabolic-Telescope-Mirror-/201456627192) and DIY the rest..?

[CAAD9]

Hi Steve,

I have a Saxon 10" pusher and a 14" sky watcher goto. The 10" I chose first ( after exhaustive research) with a 14 as a close second but ultimately rejected option.
My 14"goto followed about a year later when an opportunity came up to buy one new whereby someone else had ordered and paid the deposit and then bailed. I only had to pay the balance. Armed with spousal permission a deal was struck. But I digress.

Everything has a pro and a con, and the 14 goto has heaps on both sides of the ledger. The short version is: cons are mainly to do with logistics the pros are mainly to do with the seeing.

For more detail, please see below. So here goes:

1) the 8 or 10 pusher should always come first and you should keep it after you get a bigger goto dob. You learn the sky much better with a pusher, goto makes you lazy. I have regressed in star knowledge since getting mine. I'm making a conscious effort to use the 10" regularly these days. You tick this box, so move on. :thumbsup:
2) yes in pictures the bases all look similar but they are all scaled up with each step up in aperture. Further to this point, the base of the 14 is in fact a good deal bigger than the 10", and the alt/az motors mean a massive amount heavier. The 14 is the smallest where the base can be unscrewed into 4 pieces. This is vital to an urban dweller like me who makes dark sky trips for seeing deep sky objects. But also needed domestically because with out some form of trolley even just for moving it around your own property it is too big for one person alone. For moving it around the backyard I had a dolly welded up recently so I will be able to keep it all assembled, cables and all, while at home. Please see picture. Up to know I had the ritual of disassembly and piece by piece movement just to shift it 20m from my study to the garden dark spot. A laborious process!

Ok, that's pretty much all the negatives out of the way.

3) the views in the 10" are fantastic, and the 14 is simply mind blowing! :eyepop: I've looked through a 16" as well. Not as big an improvement in seeing from the 14 as the 14 was from the 10, but still better, no doubt about it. Aperture wins every time!
Deep sky objects come alive in the 14". If you are into galaxy structure, which I am, you will love it. My brother in law is a constant companion on dark sky trips. One time he described the Grus Quartet as 4 "bright galaxies" To a friend in an email or something. His correspondent replied he had never heard anyone describe the Grus quartet as "bright". Admittedly in the 10" those galaxies are just smudges.
4) views of the planets are more detailed than in the 10" but demand a different discipline when observing. Atmospheric disturbance is a definite factor in the 14", and you can't really get away from it. But if you are willing to accept that within a 30 second window you'll have 5-10 seconds of excellent seeing, those 5-10 seconds are awesome! The detail is amazing. The GRS is positively bright in the 14" and my favourite part is the wake in the southern equatorial band left behind by the GRS. The eddies and vortices that trail behind it are mesmerizing. Last week, the BiL and I watched the double transit of Jupiter in both the 10 and 14 side be side. Interesting comparison. The view in the 10 is more consistent but does not give the same highs as the 14.
5) goto function is reasonably accurate when you search for objects and tracks very well once you have found and centred your target. I find that the goto is usually out by up to 1 degree when you first seek a target, so a low powered wide field eyepiece helps. But I also find that the error is consistent through the night. Once you get used to it, you'll know where to always look.
6) The tracking function is great when sharing the viewing with others. This is one of its best points. Everyone gets as many turns as they want, you don't have to keep re-centring between each viewer. Swap eyepieces, filters, go make a cup of tea, no worries it will hold it. I've done all of these, I'm not exaggerating this point one bit. I don't think the tracking is accurate enough for astro photography. But I'm no expert there. For visual kit is perfect.
7) it does the dob nudge with far more subtlety than you or I can achieve. Again a great benefit for viewing at high power as the view settles quickly after every movement. I find this a huge bonus for planets and planetary nebula.
8) I'm 185cm tall, the 14" is the ergonomic choice for people around my height. I can break my back stooping over the 10" and needed a step ladder for the very top of the 16" altitude range. The 14" is just right for me.

One last point, and this can be either a pro or a con. These are fast scopes, so demand higher quality eyepieces. And once down the premium EP path you go, forever will it rule your observing destiny! Even with your smaller telescopes. :shrug:

For me aperture wins every time, but a 14" goto is not a beginner scope. You need time to learn its quirks and to get used to it. But if you are patient and keep at it, it will reveal wonders. I'm very happy with mine because of the things I've seen through it and who I've been able to share it with.

Anyway, that's enough verbal diarrhea from me. Feel free to get in touch if you have more detailed questions.

Good luck.

Adam

[raymo]

Great post Adam, but sadly, you omitted the o in Diarrhoea. :lol::lol:.
cheers Raymo

[janoskiss]

Thanks Adam. That is excellent info. Your post pretty much covers everything I wanted to know. Sounds like they are exceptionally good scopes for the money.

But I will have to mull it over (and I'll have plenty of time to do that because I won't have the funds any time soon to buy one) - whether to be lazy and buy something off-the-shelf or buy the optics and build most of the rest.

I am not that attracted by the GOTO, but more so by tracking. I quite enjoy doing things old school with star charts and star hopping my way to a target or just exploring a region of the sky visually. And these days there are also lots of other electronic aids for helping one navigate (tablet PCs, phones etc).

I guess will stick with my 10" for this year (or till winter's over at least ;)) and try and improve on that --- see if I can add tracking to the existing mount. I do have two capable stepper motors with controller boards and a Raspberry Pi 2 that has not seen much action yet. I am a little stumped though on how to mechanise/motorise the movement: along the alt-axis especially. Everything I've thought of so far (and seen others do) is either fairly cumbersome or flimsy.

But since having permanent access to some excellent dark skies (thanks to one of my in-laws), I am also very keen on eventually getting some more aperture and spending more time with the Cosmos. I am liking what I am seeing at http://www.hubble-optics.com/ (I forgot about these guys till I linked one of their ebay ads in my earlier post, just from an old bookmark in my browser).


I can never remember how to spell that word either. :P

[CAAD9]

Yeah, sh!t happens.

Thanks

[AEAJR]

I know the Orion GoTo dobs can be moved manually if you wish without messing up the GoTo orientation. Are the SkyWatcher scopes likewise equipped?

An alternative to a Goto might be something like the Orion Intelliscope. I have my eye on the XX14i because I can reach the eyepiece without a stool even at zenith.

You punch in M42 and the screen tells you where to point the scope. Not motors and no tracking. Or you can put in RA/Dec and it will tell you where to point. Or you move it manually and hit Info and it will tell you what you are looking at.
http://www.telescope.com/Build-A-Scope-14-IntelliScope-Truss-Dobsonian-Telescope/p/102037.uts?keyword=xx14i

I don't know how available these are where you live or if Skywatcher has something similar. I have the XT8i Intelliscope. I use it manually about 50% of the time. I certainly don't use it for planets. But when I am hunting DSO I tend to use it a lot.

[Allan_L]

Great write up Adam! :thumbsup:
Lots of detail and useful information.

YES! Ed, the Skywatcher can be "pushed" in both Alt and Az without effecting the alignment. This is a great feature. ("dual encoders" on each axis).

As good as the Skywatchers are, Steve, have you considered the Orion (goto or push to as mentioned previously). See this review:
Orion XX14i Intelliscope Truss Tube Dobsonian (http://www.iceinspace.com.au/41-651-0-0-1-0.html)
I have looked through this scope many times and it is of a very high quality (IMHO).

The differences in bases referred to by Russ I believe he was referring to the fact that the SW14 and above the base is designed to be disassembled easily for ease of transport etc, while the SW12 and lower, the bases is not easily disassembled and generally stays in one piece.
The Orion 14 above also disassembles for transport.

[CAAD9]

[QUOTE=janoskiss;1237640]

I guess will stick with my 10" for this year (or till winter's over at least ;)) and try and improve on that --- see if I can add tracking to the existing mount. I do have two capable stepper motors with controller boards and a Raspberry Pi 2 that has not seen much action yet. I am a little stumped though on how to mechanise/motorise the movement: along the alt-axis especially. Everything I've thought of so far (and seen others do) is either fairly cumbersome or flimsy.

Steve,

I'm not one to dismiss aperture fever, this cruel disease is no myth. But there is SO much to explore with the 10" there is everything right with not rushing in.

If you do mechanise it, please share it on IIS I would love to see what you do.

Thanks for the kind words everyone.

Clear skies to you all.

A

[janoskiss]

Thanks for the further replies everyone. I see now what you mean (Ross) about the bases (thanks Allan).

Yes, the Orions do look good; they use the same Synta optics afaik, but the mount and OTA look more sturdy.

Not so interested in the Intelliscopes: what I really want is the motorised tracking; the object finder I can take or leave.

[Allan_L]

Good Come Back!
BTW, according to Wiki:
...well you get the picture. :P

[raymo]

I would guess that omitting the o is very probably the American spelling,
which I try my best to resist.
raymo

[glend]

A sold my big dob last year, great scope, but it was a problem to move, even around my yard, and required a lot of room to transport to a dark site. The weight was just too much for me. I think many of us go through 'apeture fever' until we reach a personal limit of tolerance for the increasing inconvienience. Think hard about how you will deal with storage, moving it around, and offsite transport. Compare the views if you can, and remember that the initial 'awh' of bigger apeture quickly becomes routine. I wish I had kept my 12" instead of 'upgrading' to the 16".

[janoskiss]

Thanks Glen. I know what you mean by the initial wow-factor quickly wearing off. I've gone through it once before, going from 8" to 12", only to soon sell the 12" and get a 10" for sake of usability, convenience and better quality optics.

If I got a big scope, it would be permanently housed at a dark site but it would still have to be moved in and out of a shed and possibly also around the site (it's on a hilltop but there are trees about). I expect some sort of custom wheeled trolley arrangement would be essential.

[CAAD9]

Oh. Don't know about that, the views through the 14" are visibly :lol: better than the Ten. I suppose that's not in dispute. But the Wow factor? Well it has not worn off on me yet. Every trip to the dark there is always something faint made visible by the big dob that makes you go : WOW!

And that's why I'm always happy to go through The Ritual :disassembly, packing, drive, unpacking, reassembly....:rofl: every time I go to a dark sight.

Having said that, the Ten was awesome last night. It takes no effort to get it out on the hand trolley (see pic) do a quick look at Jupiter and then run back inside when the drizzle comes. :thumbsup:

The attached picture was taken while writing this post. I'm not exaggerating, it took all of 3 minutes to get the dob out to my northern vantage point, iPad in one hand I might add, take the photo and then drag the scope back inside.

So, you can't lose Steve.

P.s. Alan, Raymo, Thank you for the kind words.

[kittenshark]

Skywatcher is about to release to the market an 18" GoTo truss dob and an 20" GoTo as well. We were offered the 20" for a display piece but it's going to be taking major real estate on the showroom floor so it's going to be special order only.

[janoskiss]

I assume you're running a telescope shop. That major real estate would be a jawdropper for most of the customers who come into your shop. Maybe it'd be worth it.??

[kittenshark]

I was really on the fence on this one... It would be a beautiful scope indeed! We've had a few big scopes on display, but most of the people who bought them didn't even come into the store; they ordered them online.

And they were a b**** to pack up too... and putting something up on display increases the risk of it being damaged, getting dust on it, trip hazard etc.

It's nice to have something for people to aspire to, but usually it's the beginners who come in and want to look/see/touch/talk to someone. Most won't buy a big scope. Or "big" for them may be limited to a 10".

Choices, choices...

We're looking to move to new premises soon as well--likely a warehouse/bulky good showroom; we've outgrown the little shop here, so in the near future, we definitely have some huge scopes on display! :thumbsup:

Spoiler alert: there will be maybe only 2 of the new StarGates on their way to other dealers shortly. Might be awhile before more are on the way.

[janoskiss]

Where is your shop btw? Asking as a very non-local person who has never been to QLD. (But your town's on my list of things to do before it's reaping season in my corner of the multiverse.)

I still tend to think a slick 20" truss Dob would pull in more customers, but knowing what I know about running a telescope shop (i.e., nothing) I'd bet my life savings that you made the right decision and I'm just dreaming.

Good luck with the move!

[kittenshark]

We're about 20 min from Brisbane. See http://www.sirius-optics.com.au/visitus and you'll also see a pic of the shop, and you'll know what I mean by no space... and we've got even more stock now. (Reminds me, I need to post up a new photo of the shop.)

It's customers (and potential customers) who give the most valuable feedback, so sharing your thoughts is much welcome! :)

I think you guys have convinced me to consider again having a big scope in the shop--the problem is figuring out where to put it and whether to wait till we move. With our current premises, I'm terrified that one day someone will trip on a scope because there's just so little room to move--not so much damaging the scope, but hurting themselves.

If you have a big ticket item that costs thousands and thousands of dollars, suddenly the $500 scope looks very cheap. ;)

[kittenshark]

Dammit you guys. You talked me into it. Skywatcher rep came in today and I told him we're taking the last one they've got and he's placing the order tonight.

So I have the 20" Skywatcher GoTo on the way to the shop this week.

Fortunately we have sold through some of our floor stock so there's a little bit more room now to actually set it up. It's got a shroud and a mirror cover so dust won't be a problem, hopefully.

If all goes well we're going to celebrate its unveiling on the coming weekend!

:party2:

[janoskiss]

Your showroom floor does look very busy already in that photo. Good luck accommodating the 20"! I'm sure it will be jaw-dropping gorgeous. :thumbsup:

[kittenshark]

4 boxes totalling 125kg in mass and needed a forklift to get it off the truck. :eyepop:

Unboxing and assembling it on Saturday--come down and see it!:hi:

But can't help if it gets sold before then... Skywatcher says they aren't getting any more for several months.

So I'm in box hell and all because someone here suggested that I get it as a showpiece. (OK, their sales rep also is guilty but we love him anyway.) :P

[AEAJR]

If you use it right it will probably help you sell a lot more 6 and 8" scopes. And that special someone will walk in and just have to have the BIG one.

Best of luck with it.

[barx1963]

Looking forward to seeing photos of it all setup in the shop!!

Malcolm