I've had the 12, which is fitted with an Argo navis for about 18 Months.
Seeing as my interests are becoming more and more photographic, I may be offering this set up for sale soon.
That definitely sounds interesting. The only thing I'd be worried about is postage and not having warranty.
I'm still only new to astronomy. I only own a small 60mm refractor which I've had for years. I want to upgrade to see more things like galaxies and nebulas though. I've been looking around a lot lately for a telescope that wont put a massive hole in my pocket, and dobs seem like the best way to get aperture for less, especially since I'm a newbie.
How portable is the 12" dob? I've got to get it from inside to out and back again, so I don't want to have something thats too much trouble to move.
Both are good to deal with as far as i understand.
I had the Bintel 12" dob before upgrading and wheeled it out of my shed on a trolley for each session. No Problems. It is a bit of a handful if you're going to transport it by car a lot. Quite possible, depending on your car and your preparedness to lift 20kg or whatever the OTA is. I had no problem with this and it was fine in my Camry wagon. Other people find the 10" more portable and you don't lose a lot in light gathering power (about 30%)
Andrews Communications was the sight I was looking at buying it from actually.
I wont need to transport it in a car often. 10" would be best for me then if there isn't a lot of light gathering poer lost and it's more portable. I just need to take it in and out of the house. Through there is a small (about 15cm) step down to get out my door, would that be much of a problem for a 10"? I can't seem to find it's weight.
GSO are now making quite good optics. I recently spoke with an optician at our society and he was saying that the figures coming from their parabolics are as good as the best commercial makers in the US. GSO have got their systems for manufacture well under control. In fact they make an RC now which is also very good. I would say that if you buy from an Australian retail you will get a good GSO with warranty.
I've only had use of a GSO 8", fine scope. Never heard of issues with this brand with their dobs. Oh, just remembered, I did have a peek through a GSO 12"- just as good.
If you are concerned about the weight, you can take the mount first outside then go back for the scope. Same goes for the 12".
If you then want an even more compact & easily transportable scope, you can take the optics from the, say, 12" and make your own truss scope. My 10" scope is tiny when packed, see pics. I've seen this two pole design used with 12" & 17.5" dobs.
I've got a 10" GSO dob and I really like it. The optics are pretty damn good, I have viewed DSOs at up to 600x with very nice results. It stacks up very nicely to my premium 12' dob.
I have to carry mine down 3 steps and it's no trouble. Main thing is, take it easy on the steps, don't rush! The 10" tube I think weighs about 17kg, the 12" will be ofcourse considerably larger both in bulk and weight. The 10" will fit across the back seat of a car, but the 12" i think won't.
I've got a 10" GSO dob and I really like it. The optics are pretty damn good, I have viewed DSOs at up to 600x with very nice results. It stacks up very nicely to my premium 12' dob.
I have to carry mine down 3 steps and it's no trouble. Main thing is, take it easy on the steps, don't rush! The 10" tube I think weighs about 17kg, the 12" will be ofcourse considerably larger both in bulk and weight. The 10" will fit across the back seat of a car, but the 12" i think won't.
Do you think dobs would be the way to go for a beginner like me? Or am I better off getting a goto/auto tracking scope so I can find more things? I have a program called Stellarium which is useful for finding things, but I want to view things with the family, so I don't want to be chasing planets and things around, only to have the planet move out of the FOV before they can see. The only problem is the price. They're so expensive.
Lots of beginners start with dobs. It does take a little while to learn to find things, but you will be able to find a lot fairly quickly. "Atlas of the Southern Night sky" is a very useful book with maps of each constellation and 4-5 interesting things to look at in each. I use my dob at school nights etc - even at high powers, things don't move out of view that quickly - i move it every now and then, but its not hard for people to get a good view.
Star hopping is a great way to learn about the sky IMO. Mind you, going to some star nights or astro camps helps the learning happen much more rapidly.
I'm thinking about buying a Guan Sheng 10 or 12" dob, because of it's low price.
Does anyone know what the quality of Guan Sheng products is like?
I bought a 12" dob from Andrews Communications and haven't looked back. I wasn't to sure about buying it as I had never heard of the name but you will find that 90% of dobs are from GSO and have just been rebadged.
The service at Andrews Communications is top notch. They had no problems in answering any of my questions. Once I had depoisited the money into their account the telescope was knocking at my front door 4 days later in good condition.
Do you think dobs would be the way to go for a beginner like me? Or am I better off getting a goto/auto tracking scope so I can find more things? I have a program called Stellarium which is useful for finding things, but I want to view things with the family, so I don't want to be chasing planets and things around, only to have the planet move out of the FOV before they can see. The only problem is the price. They're so expensive.
Before you buy anything I strongly suggest you go to a star party & see both dobs & the 'goto' scopes in action. This way you can tyre-kick & put your mind at ease. There are several around Sydney this weekend if you can get yourself to one. Check out the 'star party' forum.
Using a dob, you will quickly familiarize yourself with the sky. A 'goto' may find stuff faster, but you might lend yourself to missing out on achieving this familiarity & intimacy with the sky.
If you are concerned with the object drifting before being seen, the trick here is two fold with a dob- use moderate power, and place the object just out of FOV & allow it to drift into it.
I love my 12" dob. Go To scopes sound easy, but I had a small one for a few months and ended up selling it as I found I could find more with a dob and a good atlas. Also you get more inches for your $ and a greater sense of achievement when you find that elusive little DSO you have been hunting.
If moving it is a prob, build yourself a trolley as per mine in this thread http://www.iceinspace.com.au/forum/s...ad.php?t=47433
There's a lot to be said for a Newtonian reflector on a Dobsonian mount (sorry to be picky but there are two different issues - optical system and mount). To add to the points already made, the Newtonian reflectors that we are discussing have relatively wide fields of view at low power, which not only makes for some nice views, but also makes finding objects easy. But the Guan Sheng newtonians also take higher powers well and either ten or twelve inch is serious aperture.
My experience has been that some time with a Dobsonian mount - which is simple and rugged - was great for learning my way round the sky, and also for increasing my appreciation of what I see. It's also much easier to set up, so good for quick views. If you only have half an hour, some nights, you don't want to be put off by a big setting up job.
I have both ten and twelve inch Guan Sheng Dobs. The twelve is a significant improvement on the ten in terms of light-gathering power (144 to 100, because the light-gathering area increases with the square of the diameter).
But it is a big telescope. I always move it in two pieces, tube and mount, and I wouldnt want to carry a bigger tube (it's heavy enough, but it's also long and thick!).
I usually carry the ten outside in two pieces, as well, but the tube is that much lighter and easier to handle. I don't think there's any problem with carrying in two pieces - its the easiest way to do it in many cases.
However one pleasing aspect of the twelve is that you can stand the tube on its end, because the collimation screws are recessed, which is not the case with the ten, so you have to lay that down while you carry the mount.
The ten is of course easier to fit in many vehicles - its almost a foot shorter than the twelve. I can put the ten across the back seat of my Rav 4 which means room for a passenger, or I can put it lengthways with one back seat down, which means room for two passengers. But the twelve, it's just me and my telescope.
Having got a twelve, I wouldn't want you to think I am dismissive of the ten. They are both very fine telescopes, and I was very happy with the ten for several years before beginning to think of a twelve. And the ten was so easy to move I could easily take it out for 20 minutes if that was all I had - the twelve is a bit more of a commitment.
You know your own situation best, so I won't say ten or twelve, but if you can get to inspect examples of these instruments before you buy that would be helpful. And, the other thing to think about is that this may well not be the last telescope you buy, so there's some sort of combination of your budget/site/experience/available time. Think of it as a telescope for a few years - you can't predict what will be around in five years time, or perhaps how your observing interests will evolve.
Thank you to everyone for your very helpful responses!
With regards to size, it's looking as though 10" is best for me. Even though I lose a fair bit of light gathering power, I get the bonus of portability and a cheaper price, which means I can buy some eyepieces, an Argo Navis, or maybe put the money towards a telescope later on.
Just one more question, how well does the 10" and 12" hold collimation?
Just one more question, how well does the 10" and 12" hold collimation?
Usually not as good as an 8" or 6" BUT depends on whether you have improved the primary mirror support with stronger springs.
But one must always check collimation on a newtonian reflector at the start of (and maybe again during) every observing session, particularly if the scope is moved/transported between sessions.
