Hi everyone , im new to the forum and new to astronomy and am looking for a bit of advice in buying a new scope . I have stumbled upon " Andrews communications " thanks to this forum , they have a 12" Guan Sheng Dob selling for $799 , so my question is , is this as good a deal as it looks , or shoud i be looking at another brand of dob .
I just had a look at the dob on the site and its. 12"F5 and for the price, I'd say its pretty good value for money. I'm not sure how easily it moves or if it sticks for small adjustments, these are best to try out in the shop.
But a 12 inch would be quite heavy. So do factor that in
Cheers
First grade 12" (300mm x 1500mm) Dobsonian reflectors with truly outstanding 1/12 surface wave BK7 mirrors and 2" focusers and 2" to 1.25" adaptors.
Resolving power; 0.38 arc second.
Limiting magnitude; 14.9.
Includes a right-angle correct image 8 x 50 finderscope, 2" Crayford style microfocuser with 10:1 fine focusing, a 2" to 1.25" adaptor, fan and premium GSO 9mm, 15mm and 25mm 1.25" Plossl eyepieces!
GSO ASDX Dobsonians now have knurled collimation knobs fitted to the primary mirror cell. This feature allows much easier and more
precise optical alignment.
Large knurled aluminium side knobs adjust tube tension
If you want a good easy to set up scope for visual observing, then this is a good deal (IMHO).
Only question I have is whether you will be comfortable lugging it around, being a 12" FULL tube scope.
Perhaps a bit extra to get a collapsible scope may pay off in the end if it is easier to move about. Or drop back to a 10"SW collapsible (flex dob) for the same price.?
The 12" solid tube dobs wont fit across the back seat of the average car. Check it will fit in your vehicle before deciding (if you plan to drive to a dark sky site). Thats why I went with the lightbridge which breaks down into smaller pieces (but optically it is of the same quality as the GSO-same manufacturer). $799 for a 12 inch scope is brilliant value.
Hi again guys , first of all , many thanks for you replies , the size and weight of the scope wont be a problem as im only going to need to move it 3 or 4 metres on flat ground " i was thinking some kind of trolley system " and it will fit in my 4wd no problems , it is the quality overall that i was most concerned about , but its seems the people that make the scope also make other scopes and components , just re-labelled , looks like i may give this dob some serious consideration , thanks again folks .
Hi again guys , first of all , many thanks for you replies , the size and weight of the scope wont be a problem as im only going to need to move it 3 or 4 metres on flat ground " i was thinking some kind of trolley system " and it will fit in my 4wd no problems , it is the quality overall that i was most concerned about , but its seems the people that make the scope also make other scopes and components , just re-labelled , looks like i may give this dob some serious consideration , thanks again folks .
Good large aperture scope for the price, best value scope in Australia IMO. I've had Skywatcher and Saxon Dobs I like my GSO the best. If you'd like to ask any specific questions or want more pics let me know. Cheers.
I have a GSO 12" dob and some comment I can make
The Alt movement is really nice and easy to adjust, the Az movement can be a little loose, it will swing around in a decent breeze. Optics are good, but it is still a budget scope. One point is that the glass is BK7 not Pyrex. The collimation setup on mine was a bit dodgy, the springs simply not strong enough and the adjusting and locking screws pretty average. Replaced the lot with Bobs Knobs. I notice thaey now have large knurled knobs on the primary similar to Bobs, but the main thing is the springs.
The bases are just chipboard. I made sure I waterproofed the whole thing, superglued all the seams and siliconed where the parts joined. Haven't had any problems but it has never been really wet.
They often come without any instructions!!! Mine had a set but for the previous model which was put together differently.
Be aware that the tube is big and heavy, unless you enjoy carrying around a hot water heater, get a trollet to help move it around.
All that being said I have had years of enjoyment out of my 12". Great value for money, just be aware it is a budget scope.
Thanks for all of your advice guys , you have set my mind at rest that this dob is indeed a good first scope , i will contact the dealer asap to get things happening , will post again when i take delivery , maybe do a short review for others that may be considering the same scope , and of course i will probably have a dozen more questions for you guys .
OK, yes, I,m getting more and more robust every year.
I know they are cumbersome as far as dimensions, but any idea what the weight would be?
Not the 10"
My 12" came in two boxes. The disassembled mount was 21 kg and the OTA was 21 kg so about 42 kg all up for a 12". So you are lifting no more than 21 kg at a time.
The 10" would be a bit lighter, but I'm not sure by how much, maybe around the 16-18 kg mark for each component???
I bought my 10" GSO DOB from Andrews just over a week ago. I'm also a beginner, and despite having nothing to compare to, I am really pleased with it.
My scope is about 17kg and the base, I'm gessing, about 12-15kg. I carry mine up onto my rooftop and can do it relatively easily in two trips. I seriously doubt I could carry the 12" though.
Saying all that I'm jealous of you getting the 12"!
Jupiter was the best I've seen it tonight, despite very bad light pollution in Brisbane! As someone said previously though 1500mm is a big scope to lug about.
Hi everyone , im new to the forum and new to astronomy and am looking for a bit of advice in buying a new scope . I have stumbled upon " Andrews communications " thanks to this forum , they have a 12" Guan Sheng Dob
Haz
Harry,
I would just like to reinforce the fact that a 12 inch is nearly always a large and heavy instrument, and therefore it is likely to be difficult to set up and use for the beginner.
A more practical aperture, for the beginner, is 8 to 10 inches.
It is remarkable how often beginners buy 10-12 inch telescopes, and then they find that the instrument is too difficult to lug around and to use, let alone to carry it to a dark sky site. I have seen these huge unused "white elephants" many times in my over 37 years of using many different telescopes.
I strongly urge you to read the discussion, in this forum, entitled "Recommendations for a beginner telescope", as it deals with the practical side of using telescopes of different sizes. The discussion entitled "Semi-beginner semi-first scope advice" deals with the options for some of the smaller sizes (4-6 inches).
The disassembled mount was 21 kg and the OTA was 21 kg so about 42 kg all up for a 12".
That's an interesting data point. The 8" GSO Dob (that a lot of people will be familiar with) weighs about 10kg for the rocker box and 10kg for the tube. So, both parts of the 12" Dob will weigh as much as the entire 8" Dob.
Also, keep in mind, what you can and cannot carry doesn't just depend on its weight. I could carry a 20kg tube easily, but a 20kg rocker box not so much, because of its awkward shape.
Hi again everyone , 12" dob was ordered at the beginning of the week so should arrive any time now , cant wait . Once again many thanks for your comments and advice . It would seem the only downside to this scope is its size and weight , its ok it wont be a problem , i intend to put wheels/casters on the bottom , to move it from where its going to live to where it will be used involves sliding a door open and rolling the scope 4-5mtrs on flat concrete , to get it in my car , i am able to reverse the Patrol right up to where it will live , so no carrying , just a lift into the back of the car . Thats the theory anyway .
That's an interesting data point. The 8" GSO Dob (that a lot of people will be familiar with) weighs about 10kg for the rocker box and 10kg for the tube. So, both parts of the 12" Dob will weigh as much as the entire 8" Dob.
Assuming the identical design, and assuming identical materials with identical densities, an object which is scaled up in dimensions by 50 percent, which is the (very) approximate case for the scaling up of an 8 inch into a 12 inch......
the 12 inch has to weigh three times as much as the 8 inch.
(if you double the dimensions of something, you end up with a volume that is 8 times greater!)
Now it is possible to save weight by clever design in the large telescopes, but, experienced amateur astronomers know that a 10 inch telescope is usually a "large and rather heavy object".....though there are a few exceptions to this rule.
Experienced amateurs also know that a 12 inch is always a massive object.
As I keep on saying in these beginners forums: "the best telescope is one that you are able to use frequently and easily, without great struggle and stress"
That is why I recommend an 8 inch Dobsonian for beginners!!
