This is my first post on iis! This must be the shortest time I've ever lurked on a forum before joining and posting.
Anyway, I'm a new astronomer with effectively zero practical experience with scopes. (I've observed during a university astro course and at Uluru but never operated my own.) I've learned some things from the many beginners' guides online, but there's a lot I still don't know. What I do know is that I'd like to have my own scope sooner rather than later!
I'm looking at the 12" Skywatcher Dob (non-collapsible) at around $800. The 12" collapsible is too pricey - even Andrews are selling it for $1500. The 10" collapsible is around $850, and for completeness I'll mention that the 10" Dob (non-collapsible) is, well, also an option, and by far the cheapest. So the options I'm currently looking at are the 10" collapsible and non-collapsible, and the 12" non-collapsible (I'm sure there's a better term for non-collapsible, like tube assembly or something.)
I should add that I also have my eye on a used 6" Guang Sheng reflector with motor drive on an equatorial mount. Also, I'm on the coast here in Sydney and have clear eastern skies from my balcony, so I'll be observing here, but I'll also want to take my scope out occasionally for observing sessions which will require lugging it down a flight of stairs and into the car and then out into a field ... you know the drill.
That said, I have a few questions for you:
1.Do any of you have any experience with these Dobs? Are there any disadvantages to the collapsible models (dew/ambient light interference/etc)? What are the advantages and disadvantages of both - is it just portability vs price, or are there other factors? What do you suggest?
2. I don't know much about things like collimation, diffraction limited, and various other practical/optical issues. What is there to know about these Skywatcher/Bintel scopes in this regard?
3. Eyepieces: what do I need, to begin with? And filters: what should I start with, apart from a decent moon filter?
4. Are these scopes simply too heavy? This is the only thing that keeps going through my mind! Are the collapsible Dobs a good compromise?
5. Any other suggestions?
Thanks guys - can't wait to hear from you!
- darkskybondi
Last edited by darkskybondi; 22-12-2008 at 12:11 AM.
Be aware that the 12" solid tube is huge and hard to move around. I have a statesman which is a very large car and my 12" dob would only fit in by laying the passenger seat flat and lying the brut in from the rear drivers side passenger door and across the front passenger seat banging on the glovebox. A 10" is easier to manage and can be put on a gem mount a whole lot easier.
Be aware that the 12" solid tube is huge and hard to move around. I have a statesman which is a very large car and my 12" dob would only fit in by laying the passenger seat flat and lying the brut in from the rear drivers side passenger door and across the front passenger seat banging on the glovebox. A 10" is easier to manage and can be put on a gem mount a whole lot easier.
Thanks for this advice, mate. The skies have been partly cloudy tonight and it's cold here in Bondi but I got some excellent viewing in with my 8x40 binoculars, no tripod.
I'm just wondering if the 30-40cm difference in length between the 10" and 12" tubes is worth sacrificing the extra aperture. Is there a massive difference in seeing between a 10" and a 12", or will I find it much of a muchness as a beginner?
My advice is: if you can find a 12 " solid tube SW980 dobsonian for $800, BUY IT!
By the way, where did you see it at that price? Coz I want one too.
I have heard rumours the collapsible ones may have issues with collimation (mirror alignment after extending / retracting) but this isnt confirmed.
Cheers
Chris
Thanks for this advice Chris. Andrews is selling these things CHEAP but they're on holiday till January 12, I think they said. Meanwhile I think you can get pretty similar deals at any of the major scope shops round town.
Have you heard anything about the optics on these rigs? I read somewhere that you shouldn't buy anything but the "name brands" - are Skywatcher a decent brand?
Thanks for this advice, mate. The skies have been partly cloudy tonight and it's cold here in Bondi but I got some excellent viewing in with my 8x40 binoculars, no tripod.
I'm just wondering if the 30-40cm difference in length between the 10" and 12" tubes is worth sacrificing the extra aperture. Is there a massive difference in seeing between a 10" and a 12", or will I find it much of a muchness as a beginner?
The initial views I got from the 12" where stunning, I'd only ever had 8" scopes before as they mount well on a German Equatorial Mounts for photography. A 12" gathers almost twice the light of a 10" but you need to concider the logistics. You will not be able to move it without a trolly or another person.
Mine lives outside and is harnessed to a trolley so I can roll it into the backyard and set it up.
In Australia, Skywatcher and GSO are the name brands - they're good scopes. You won't go wrong with either of them.
The 12" is the size of a water heater. You need to consider the portability. I started with a 10" dob and it was a fantastic mix of aperture and portability.
The only reason I upgraded to my 12" newt was for planetary imaging - I've got the 12" newt on an EQ6 but in general, I prefer newtonians on dobsonian bases for visual observing.
The 12" newt OTA is about 21kg. And not only that, it's long and can be awkward to carry. If you want to observe out of city lights, it also needs to be able to fit in your car. I use the half-circle foam cutouts that came with the scope to sit it on in the car.
The initial views I got from the 12" where stunning, I'd only ever had 8" scopes before as they mount well on a German Equatorial Mounts for photography. A 12" gathers almost twice the light of a 10" but you need to concider the logistics. You will not be able to move it without a trolly or another person.
Mine lives outside and is harnessed to a trolley so I can roll it into the backyard and set it up.
Excellent advice, Tandum. What does your 12" tube weigh? The key for me is that I'll need to be able to lift it out from my room to the balcony which is a few metres, and then be able to set it in the mount, preferably all by myself. I figure I could handle 20kg over short distances. I heard these things were 20kg but a bloke at one of the stores here in Sydney gave me wildly varying figures between 35kg and 50kg. Clearly this would be excessive. However, if the tube were around 20kg, I could always get a helper to load it downstairs and into the car on the rare occasion that I took it to star parties.
So.. how heavy are we talking?
Depending on your answer, I may end up compromising and going for the 10" after all. Would save me a lot of cash too. And then eventually I could save up and buy a 12" to keep at home.
In Australia, Skywatcher and GSO are the name brands - they're good scopes. You won't go wrong with either of them.
The 12" is the size of a water heater. You need to consider the portability. I started with a 10" dob and it was a fantastic mix of aperture and portability.
The only reason I upgraded to my 12" newt was for planetary imaging - I've got the 12" newt on an EQ6 but in general, I prefer newtonians on dobsonian bases for visual observing.
The 12" newt OTA is about 21kg. And not only that, it's long and can be awkward to carry. If you want to observe out of city lights, it also needs to be able to fit in your car. I use the half-circle foam cutouts that came with the scope to sit it on in the car.
More good advice, thanks Iceman. I still feel I'll be sacrificing some serious aperture for portability, and I feel most of my observing - at least for the moment - will be on this level of the house... this could tip the scales in favour of the 12". However, it's good to know that your 10" dob starter scope was not shabby for a compromise between portability and aperture.
So, if I settle on the 10", do you recommend the tube or the collapsible construction?
I just wheeled the whole show onto the corner of a set of bath scales and it showed 30Kgs including the base yet the trolley wheels where still on the ground. I'd guess the tube itself would be 25Kgs, almost 400mm in diameter and about 1.8meters tall.
I just wheeled the whole show onto the corner of a set of bath scales and it showed 30Kgs including the base yet the trolley wheels where still on the ground. I'd guess the tube itself would be 25Kgs, almost 400mm in diameter and about 1.8meters tall.
Cheers tandum - that really puts things into perspective. I should mention that my eyesight is not brilliant - very short-sighted with poor night-vision compounded by a fuzziness not unlike TV static across my field of vision (had this since childhood). This means, practically speaking, that when a dark sky impresses some people to their naked eye, I am not quite as impressed without, at least, binoculars.
That's the only reason I am still going to sleep on this 10"/12" question. I shall be decided in the next week or so.
Also interested in other people's opinion on how my vision affects my choice of aperture, and what people think I should get accessory-wise to begin with.
As others have said the 12" solid tube scope is big and heavy, BUT a lot cheaper than the truss mounted ones.
I have the 12" Lightbridge and even though it's a few hundred dollars dearer than the solid tube, the ease of transport and setup certainly cancel the extra cost.
Collimation is very quick and simple.
I'm happy to supply further information if you wish.
I have just bought a 12" collapsible (and we have consequently had one of the wettest springs for many years!), and have had no problems with collimation other than the usual tweak that may be needed before each use. Once set, collimation so far has held nicely throughout the night.
I am very happy with the scope, and the fact that it collapses gives natural lifting ponts from the truss supports when moving around. I lift the OTA off the base, move the base outside to where viewing will take place for the night, and then carry the OTA out. A solid 12" tube, in my opinion, would probably feel more cumbersome to carry around.
The other impressive thing I found with the Skywatcher, was the packaging that it came in. I bought mine from My Astro Shop, in Queesland, so it had to be freighted all the way down to SA. Skywatcher package their OTA's in two HD cartons, one inside each other. With this style of packaging, together with ample airspace and solid foram cut-outs around the unit inside the carton, give plenty of protection from transport issues.
I own the 10" SW, like mike said its a perfect balance of Aperature and Size, i can cart it around in a mazda MX 6 coupe, and a Lancer without problems.
Currently im designing a carry handle for the ota that i remember seeing from a computer case (Antec Lanboy) basically it has 2 rings with heavy duty clips with a strap that goes between, followed by a handle in the middle worked well. but i can carry the whole OTA out the door and onto the back yard lawn all up about 15/20 meters.
With that i can pick up the Taranchula neb, orion neb without problems. 47 tuc on good nights down to a 5mm ep.
thats what i have to say, and at $639 is pretty bloody good!
Thanks for all your advice, guys. So I haven't had a chance to get out to the shop to have a look at these scopes in person, but from what you've all said, at this point I'm looking at:
- 10" SW dob for $639 - portable
- 10" collapsible SW dob for $850 - very portable
- 12" SW dob for $760 - awkward
- 12" collapsible SW dob for $1500 - expensive
Gotta say I'm leaning towards the 12" full tube anyway but I can only make the decision after I have a feel of one. Is it THAT much bulkier and heavier than the 10?
Could I ask you guys to also address my query about eyepieces and filters? That definitely affects my decision in terms of expense. I am sure everyone has a different opinion, particularly on eyepieces, but I'd like to know how much I should be spending on them with my purchase - how many, Barlow, what types, what brands, etc. Particularly given my vision:
I don't know if it is relevant, but I am very short-sighted (-12) and have poor night vision with quite a bit of fuzz/static in my visual field (hence the desire for a larger aperture - even with a 12" I won't see quite the dazzling view that some of you blokes do - the static "interference" in my visual field means that stars that are less bright are very difficult to distinguish from the static.) The reason I mention this is particularly because the shortsightedness means I am unable to, for example, use my binoculars without glasses on - it won't turn enough to focus clearly for me. Will this be a problem with eyepieces on the scope?
well yeah they are bigger and bulkier.. the 10" is about 1.5m tall when in its cradle, and ide have to say given that the ota in the 12 is already 1.5m tall would be nearly 6 ft, also given that the base on the 10 is 500mm so the 12 would have to be 600mm at least. also the 10 is 14kgs the 12 is 21kgs. so instantly the tube itself is 7kgs heavier
As you said its all about getting enough light onto your eyes. for a normal set of peep holes a 6" will give you good views, but from what your saying you need the most you can handel.
High quality eye pieces are the only way to go for you but they are not cheap! Since i don't have too much experience with these kinds of ep's ill leave that to the professionals to comment on.
You may be interested to know that one of the the 'scopes you are looking at purchasing (the 12" Skywatcher solid tube dob) was recently reviewed in Australian Sky & Telescope July/Aug 2008 p46-48. It will give you all the weights and measures you need to know -- and a whole lot more info.
If you live in Bondi and are keen on deep sky (as the user id implies), then the 'scope will most likely need to travel in your vehicle to dark skies from time to time. It is a big 'scope (the 12" tube dob) and you should measure your car carefully to ensure it goes in comfortably before you purchase.
Remember, the best 'scope for you is one you will use the most often. Choose accordingly.
Suggest you also do a search on threads within IIS for eyepieces and advice on them -- a subject that provokes nearly as many different opinions as there are Indians in Bangalore. Eyepieces are generally a pretty subjective choice/preference. Advice is good but is no substitute for trying it out for yourself. Join a club/society and go to the field nights where you can borrow a few eyepieces from others to try them out or at least look through them in other people's 'scopes.
Just one further piece of advice on eyepieces from me -- it is better to have a small number of high quality ones than 10 mediocre ones. Use the supplied ones which are reasonable starter quality until you can save a bit more and then down the track, get ones really worth keeping for a lifetime.
12" Skywatcher Dob? Your advice please!
the 10" is about 1.5m tall when in its cradle, and ide have to say given that the ota in the 12 is already 1.5m tall would be nearly 6 ft, also given that the base on the 10 is 500mm so the 12 would have to be 600mm at least. also the 10 is 14kgs the 12 is 21kgs. so instantly the tube itself is 7kgs heavier
