Skywatcher Stargate 18"/20" goto dobs

gaseous (Patrick) · #1 07-09-2016, 04:47 PM

Hi all,

I've seen a few reviews on Cloudy Nights / Stargazers Lounge about the new (ish) Skywatcher Stargate 18" & 20" dobs, and was wondering if any of you IIS forumites have one of these, or have any additional reviews/info that might be worthwhile. My dear wife has given me permission to upgrade my 8" dob in the near future, and while a move to a similar style 16" collapsible dob would certainly do the trick, I figured due diligence required me to suss out these newer, larger, and (hopefully) considerably lighter versions. Having said that, if I need to strike while the iron is hot to take advantage of what may well have been a momentary wine-induced lapse in my spouse's good financial sense, then I'll probably stick to the 16". Cheers, and clear skies to all.

billdan (Bill) · #2 07-09-2016, 05:22 PM

Hi Patrick
These DOBS look really nice, interestingly the electronics has a ST4 port for guiding (rare for an Alt/Az).

I think Sirius Optics in Brisbane had a 20 inch on order for display.

If you have been following the Cloudy Nights thread, you would have seen this video of the 20 inch being setup at The Texas Star Party. Howie (Glatter Fame) makes a visit.

https://www.youtube.com/watch?v=oyc7...ature=youtu.be

Cheers
Bill

gaseous (Patrick) · #3 07-09-2016, 05:26 PM

Thanks Bill, yes I drooled a little bit over that video!

glend (Glen) · #4 07-09-2016, 08:13 PM

Patrick does your wife know how much these two scopes cost? They are way beyond a simple upgrade to your present dob. Andrews has the 18" listed for $6999 and the 20" for $8499, even with the 10% off sale that is still alot of money. Having gone from a 12" dob to a 16" truss dob I can tell you that the scale of the transport problem increases significantly as the weight of the rig goes up, and the view while great initially (if you can get it to a dark site) are usually limited by seeing conditions. I regard a 12" dob as a good compromise, it has good deep sky reach without being too large to manage. A 12" goto dob can do a lot and IMHO would be the logical step. Still it's your money.

AstroJunk (Jonathan) · #5 07-09-2016, 09:03 PM

Aperture rules.

Ultimately, we all settle for a scope that we can manage which is smaller that we would like. My rule of thumb when shopping around is to find the size of scope that scares you at the thought of moving and buy the next one down. That's why I settled on a 20" f5.

I have seen the Skywatcher 20" f4 at Sirius Optics and it looks quite small by comparison. The 18" must be positively diddy! Although there are a lot of bits to build it, it does make it easy to transport and it seemed to be pretty well made. MUCH better built than the smaller chipboard mounted siblings.

I would warn you though, if you go down the f4 route you will almost certainly need a Paracorr of some description and they are not cheap. The coma will be very evident and will need correcting to fully appreciate the instrument.

gaseous (Patrick) · #6 07-09-2016, 11:01 PM

Thanks guys, the wife has set me a bit of a budget, so I think the 20" is out of the question, and I might have to do some serious grovelling for the 18" in a goto model. I appreciate the comments on the coma correction as well - I figured getting down from F6 to F4 would have those sorts of repercussions. I just wish they had the stargate style in a 16" (I've heard if the 18 and 20 models sell well they might look at the smaller sizes). Might have to sacrifice 2" of aperture (and quite a bit of style) and settle for the 16" standard flextube for half the price. Cheers to all.

AstroJunk (Jonathan) · #7 08-09-2016, 08:13 PM

Quote:

Originally Posted by gaseous

Thanks guys, the wife has set me a bit of a budget, so I think the 20" is out of the question, and I might have to do some serious grovelling for the 18" in a goto model. I appreciate the comments on the coma correction as well - I figured getting down from F6 to F4 would have those sorts of repercussions. I just wish they had the stargate style in a 16" (I've heard if the 18 and 20 models sell well they might look at the smaller sizes). Might have to sacrifice 2" of aperture (and quite a bit of style) and settle for the 16" standard flextube for half the price. Cheers to all.

I very much agree about the stargate in 16" or even 14" . I'd get one in a flash for a travel scope.

I have wrestled very unhappily with a friends std 16" on a number of occasions and would recommend using one for real before parting with your money

My mate would agree!

gaseous (Patrick) · #8 08-09-2016, 10:30 PM

Quote:

Originally Posted by AstroJunk

I very much agree about the stargate in 16" or even 14" . I'd get one in a flash for a travel scope.

I have wrestled very unhappily with a friends std 16" on a number of occasions and would recommend using one for real before parting with your money

My mate would agree!

Thanks Jonathon, is it the transport/setup that's difficult, or is it a bugger to use as well? I've heard conflicting reports about how manageable it is to set up, but Astropete told me a reasonably robust chap could move it in parts without too much swearing. I'm torn....

JoelyE95 (Joel) · #9 09-09-2016, 07:33 AM

Patrick,

Myself and 2 friends have the non-goto 18" version. I really cannot complain about it. If you happen to be free, we can always meet up and you can have a look at how it all goes together and how much better it is than an 8".

Joel

gaseous (Patrick) · #10 09-09-2016, 09:00 AM

Quote:

Originally Posted by JoelyE95

Patrick,

Myself and 2 friends have the non-goto 18" version. I really cannot complain about it. If you happen to be free, we can always meet up and you can have a look at how it all goes together and how much better it is than an 8".

Joel

Thanks very much Joel, that would be fantastic! I might PM you in the next few weeks if that's alright. Alternatively if you're planning to get the scope out one night, maybe PM me if convenient and I could drop over quickly (I'm at Tanah Merah) - it might save you having to make a special effort on my account. Either way, I'm very appreciative of the offer.

Satchmo · #11 09-09-2016, 10:55 AM

Quote:

Originally Posted by gaseous

Might have to sacrifice 2" of aperture (and quite a bit of style) and settle for the 16" standard flextube for half the price. Cheers to all.

Hi Patrick Have you studied the figures ?

The 16" flex tube mount is 55kg and the tube is 38kg and you wouldn't normally try and remove the tube from the mount on these things . The base is also 850mm diameter. If you can't manage those sizes and weights on your own in and out of a vehicle then the scope may never see much dark sky ?

The 14" is still damned heavy and wont go through a standard doorway. In my experience only the 12" becomes one man portable

gaseous (Patrick) · #12 09-09-2016, 11:11 AM

Quote:

Originally Posted by Satchmo

Hi Patrick Have you studied the figures ?

The 16" flex tube mount is 55kg and the tube is 38kg and you wouldn't normally try and remove the tube from the mount on these things . The base is also 850mm diameter. If you can't manage those sizes and weights on your own in and out of a vehicle then the scope may never see much dark sky ?

The 14" is still damned heavy and wont go through a standard doorway. In my experience only the 12" becomes one man portable

Thanks Mark, you crusher of dreams!

It's certainly not going to blow away in the breeze I guess. For the most part it would be fully assembled and on a trolley with easy access through some sliding doors. If I have to do a base disassembly once a month for a dark site visit, then I'll just need to suck it up I guess (and lift with the knees, not the back!). Better than being at home listening to kids fighting. Seriously, I appreciate the input and will need to find somewhere/someone with a large dob to let me manhandle it before I get too carried away with things.

AstroJunk (Jonathan) · #13 09-09-2016, 07:02 PM

Mark beat me to it with his very accurate summary of the woes of the 14 & 16 inch beasts! the good news is that the larger scopes will be much easier to handle.

Ironically, BIG dobs are designed to be moved. You only live once, go for the 18!

gaseous (Patrick) · #14 09-09-2016, 10:30 PM

Quote:

Originally Posted by AstroJunk

Mark beat me to it with his very accurate summary of the woes of the 14 & 16 inch beasts! the good news is that the larger scopes will be much easier to handle.

Ironically, BIG dobs are designed to be moved. You only live once, go for the 18!

Thanks Jonathon, I think your last sentence sums up my feelings exactly! Cost permitting, the 18" goto would be great, but at half the price I think some sheer bloody-mindedness and a bit of occasional elbow grease would see the slightly more unwieldy 16" still be an option.

Atmos (Colin) · #15 09-09-2016, 10:56 PM

It can really depend on the telescope, in some ways I found my non-GoTo Meade 16" Lightbridge easier to move around than my current GoTo Orion 12". The base on the Orion is heavier due to the motors and stuff, the OTA (mirror part) is lighter on the Orion but the base is the killer to move. The 16" took up less space in my Mazda 6 Wagon as the Orion base is taller and has to be laid down where as the 16" base just slid in without any issues.

My next dob at some undetermined time in the future will be somewhere along the 16-24" but better designed for transportation. SDM here I come

gaseous (Patrick) · #16 10-09-2016, 07:38 AM

Quote:

Originally Posted by Atmos

It can really depend on the telescope, in some ways I found my non-GoTo Meade 16" Lightbridge easier to move around than my current GoTo Orion 12". The base on the Orion is heavier due to the motors and stuff, the OTA (mirror part) is lighter on the Orion but the base is the killer to move. The 16" took up less space in my Mazda 6 Wagon as the Orion base is taller and has to be laid down where as the 16" base just slid in without any issues.

My next dob at some undetermined time in the future will be somewhere along the 16-24" but better designed for transportation. SDM here I come

Thanks Colin, and good luck with getting a 24" SDM! Whatever I get will be carried on the back of my ute tray, so size in that respect isn't really an issue, and at home it'll be on a trolley and out through some sliding doors. Just gotta hope my back (and finances) don't give out in the near future... Thanks to all for their insight/comments.

Derek Klepp · #17 10-09-2016, 11:19 AM

Patrick of all these go to,s the 12" is the most transportable and easiest to set up.For the bigger ones(I have the 16") you really need to have it in a roll off roof obs or have it so you can wheel it out in an a flash to get the most out of it.And the trolleys you can buy really aren't heavy duty enough so you will probably have to fabricate one yourself.Also I can see myself replacing the chipboard structure with ply at a later date.
Another way to get good value from these scopes is to hook a video camera up the views are very good indeed.
As for price justification one look at Omega Centauri or Tuc more than makes it worth it.
Cheers Derek

gaseous (Patrick) · #18 10-09-2016, 11:31 AM

Quote:

Originally Posted by Derek Klepp

Patrick of all these go to,s the 12" is the most transportable and easiest to set up.For the bigger ones(I have the 16") you really need to have it in a roll off roof obs or have it so you can wheel it out in an a flash to get the most out of it.And the trolleys you can buy really aren't heavy duty enough so you will probably have to fabricate one yourself.Also I can see myself replacing the chipboard structure with ply at a later date.
Another way to get good value from these scopes is to hook a video camera up the views are very good indeed.
As for price justification one look at Omega Centauri or Tuc more than makes it worth it.
Cheers Derek

Thanks Derek, that's valuable info, particularly the bit about Omega Cent. an 47 Tuc!

Adox (Adriano) · #19 25-10-2016, 07:50 AM

This week I will partecipate to the VicSouth Little Desert Star party and I will bring a SkyWtahcer 20" Go-To for public observation. Is there anybody who will be there?

geolindon (Lindon) · #20 19-11-2016, 11:21 AM

G day Patrick (et al),

what did you go with?

i also would like more info/reviews on these 'scopes.
the price for the 18" push/pull is now down to $5k at Astro Pete's.
i'm looking at getting a slide-on ute van and one of these would facilitate a smaller more economical van.

regards, L