Finally decided to get a Dob. Now which one...

GazzMeister · #1 19-06-2007, 10:17 AM

Good morning Everyone

I posted a question about getting a Nexstar 4SE as a beginners scope on the forums a while ago. The general consensus was to go for aperture over GOTO. Well I have borrowed a Nexstar 4GT with a broken hand controller but perfect optics and I can say that it wasn't any better than the 5inch reflector that I have already. I'm a newb so I guess I thought that it would be better somehow

. Anyway I've given up on the whole tiny GOTO scopes. Maybe when I can afford a big aperture GOTO I'll get one. So I've decided on getting a big (for me anyway) aperture Dobsonian. I live in Canberra so my local options are few. I've seen an 8inch saxon for sale at Questacon for $799, but I've seen cheaper 8s for sale from interstate. Is the scope going to get smashed around if I go with the interstate options? I'm particularly interested in BinTels own brand 10inch ($699). I suppose that the telescopes at Questacon would have been shipped here anyway, and the ones from a professional telescope store would have been put together better?

On another note, how easy are Dobs to move. Where do you pick them up? Do you take the bases outside then put the tube back on or can you move the whole setup?

Sorry for the barrage of questions, I just want to get a scope that will give me a good few years to learn with.

Thanks in advance.

GazzMeister · #2 19-06-2007, 10:25 AM

Does anyone have any knowledge of Guan Sheng brand Dobs? Andrews Communications Systems has some pretty nicely priced scopes for sale. Do you really get what you pay for?

erick (Eric) · #3 19-06-2007, 10:30 AM

Quote:

Originally Posted by GazzMeister

On another note, how easy are Dobs to move. Where do you pick them up? Do you take the bases outside then put the tube back on or can you move the whole setup?

If you are talking from garage or house to backyard, with no stairs, there are those that have the whole setup on a hand trolley and move it to and form viewing location that way. Otherwise, you could carry 6" or 8" all together (make sure the tension springs are in place - keep the tube unit (OTA) from falling out). But be careful not to bang the top end (focusser, finderscope) on the ceiling/doorframe etc!

At 10", I think most would carry base separately from OTA. The OTA just lifts off and then can be laid down on its side - on something soft is best - no bangs and scratches - and be careful it doesn't roll off and fall onto the hard floor! Yikes!! Or the OTA can usually stand on the primary mirror end (on the three collimating scews usually - check the one you get - I wouldn't sit it on its fan) - but this can be unsteady - and if child or dog or friendly cat around - potential disaster.

Carry the base with either two hands underneath, or by its carry handle, allowing it to turn 90 deg to normal on lifting.

Carry the OTA cradled with one arm above and one arm below the Altitude bearings (big plastic rings on the side). Watch carefully for door frames, trees, kid's heads etc!!

iceman (Mike) · #4 19-06-2007, 10:31 AM

Hey Gazz.

Well done on deciding to get a dob. It'll give you much more enjoyment than a smaller 4" scope.

Many people do and have ordered online or over the phone and had their dobs delivered by Bintel, Andrews or MyAstroShop etc. I've only read maybe 1 instance where it was damaged? In that case the shop would arrange another i'm sure - they have insurance for this.

So don't be afraid to order interstate. You'll get much more value for money from shops like Bintel etc, than a local shop who isn't really a telescope dealer.

You will need to move the base and then the tube separately, and in reverse order for backing up. For small movements around the yard, you can put handles on the base and pick it up as one unit and shuffle around.

You can also get a hand-truck/trolley for moving the dob around as a 1-piece unit, as described in my article here. Much quicker and easier.

Newtonians are great, but you WILL need to learn how to collimate. Don't be afraid of though. Practise makes perfect, and read up beforehand. As well, get along to a local CAS meet - they'll be more than happy to SHOW you how to collimate. It's also great to make local friends who you can observe with. It just makes the hobby so much more interesting when you can share it with people.

Don't forget the star charts, red light torch, observing chair as well if you don't already have them

You will love your dob!

iceman (Mike) · #5 19-06-2007, 10:32 AM

Quote:

Originally Posted by GazzMeister

Does anyone have any knowledge of Guan Sheng brand Dobs? Andrews Communications Systems has some pretty nicely priced scopes for sale. Do you really get what you pay for?

Bintel and Andrews BOTH sell the Guan Sheng (GSO) brand dobs. Bintel just badge them differently.

MyAstroShop sells Synta/Skywatcher brand dobs, which have slightly different bases and are made by a different manufacturer (mirror as well). The quality seems on par from most people who have looked through both. Some people have a preference for one over the other, but really you'll do well with either of them.

Dujon · #6 19-06-2007, 11:05 AM

Morning, Gazza,

Not being a hefty sort of a bloke (and having a bad lower back) I shift my setup in two steps - well, actually 12 of the darn things as I'm on a sloping block. I take off the optical assembly and pop it down on my lounge room sofa, retrieve the base and cart it outside and then go back to the OTA to transport and drop it (not literally) back onto the base.

As others have mentioned, and as you'll find out, watch out for door jambs and other impediments to movement. Banging the finder 'scope or focuser is not going to assist your viewing pleasure. The base is easy as most come with a handle. The OTA I grab by the lips at the 'top' and 'bottom' as I find this an easier way to handle the thing rather than snugging it under my arm. Each to his/her own, I guess - you will soon find out the best method for yourself and your surrounds.

Whilst the whole assembly isn't all that heavy, carting the whole thing around as a unit I would not recommend. It's just too awkward unless you have a clear passage from source to destination. If I recall correctly my assembly weighs in at around somewhere between 35 and 40 Kg. Then you have your eyepieces and other miscellaneous clobber you might wish to have with you (bar fridge, spare coat or jumper . . . you get the idea).

A trolley to me is useless because of my terrain but I would imagine that if you happen to have a nice flat area from the 'scope's storage area to your viewing position it would be a right proper boon.

duncan · #7 19-06-2007, 11:09 AM

Hi Gazz,
Hopefully later today will be a write up and photo's on the 12"Bintel Dob posted into reviews. I've just sent the photos thru to Mike (iceman).
Cheers,
Duncan

Tannehill · #8 19-06-2007, 11:09 AM

Excellent idea. The dobs are great aperture for the money and a great starter scope.

The 10" dob you refer to by Bintel is a Guang Sheng Optical (GSO) scope made in Taiwan and marketed by Bintel with their sticker on it. It is very good quality for the money, and will give you years of use. Usually their showroom scopes are not the one you buy. You buy the scope in several boxes and assemble the base yourself. The tube comes almost totally assembled.

I have a GSO (Bintel) dob. I don't know the Saxon brand well but perhaps a Saxon owner will weigh in here. The GSO mirror - the business end of things, really - is very good, and probably one of the best for the money for the application for which it's designed, here. The base is inexpensive laminated particle board, and servicable. Many of us, after time with the scope, tweak our dob to refine this or that feature. Don't think they were broken to start, they're not! It's just our nature to tinker.

On a side note, later you can buy a dedicated telescope computer and encoders and make your dob a PUSH-TO scope. By this, I mean you can set it up to find any one of thousands (tens of thousands, really) objects stored in the database of this computer by pushing it to coordinates the computer displays for you. It's almost as good as mechanized GOTO, and many of us have our dobs fitted with such gear. It doesn't track, of course...you have to move the scope to follow the objects as they move, but with practice that's easy. In truth, these PUSH-TO add-ons can cost almost as much as the scope itself (computer, encoders, hardware, etc) but you'll find devotees who swear it's the best accessory they have. I’d suggest you wait on this, obviously, until you have some time at the eyepiece and know better what you want.

Weight and size and set-up ease are key issues. The best telescope is the one you use the most, regardless of aperture. And if it's too big to easily lift and transport or too complicated to set up quickly (if that’s your modus operandi) you'll find excuses not to go out...which is bad!

Best advice: find some club nearby, or even not-so-nearby if necessary, and contact them.

Who is closest in Canberra, guys?

Find some veteran dob user in the club who can meet with you and show you the ropes and help you decide what and where to buy. EVERY club I’ve known has a few enthusiastic veterans with vast experience in this or that category of telescope who can and will want to help you. As you read here on IIS, our greatest fear is that you become frustrated and disillusioned with the excess of options you have, or something like collimation or what have you, and abandon the hobby when all you needed was a quick point in the right direction from a veteran who has walked that path already.

Cheers and Clear Sky,

Scott

janoskiss (Steve H) · #9 19-06-2007, 11:31 AM

You should be able to get the 10" not 8" Saxon for under $800!
10" Saxon is great. Having owned both types of scopes I cannot tell you which is better Synta or GSO; they both have their strengths and weaknesses. GSOs are a bit more of a complete package out of the box and easier to accessorise. OTOH Syntas are made with a bit more attention to detail. You have to spend time with both to appreciate the differences. Cannot go far wrong with either though.

ballaratdragons (Ken) · #10 19-06-2007, 11:56 AM

Even though some of the stuff above sounds complicated, it isn't.

Dobs are the easiest telescopes to set-up and use.

Put the base down (facing any direction, and on any angle), and put the scope on top. Thats it!

The carrying and not banging into things is a normal precaution you'd take with any special item, so it will come naturally. Collimation will become easy and natural so don't stress about that either.

That's the wonderful things about Dobs, just plop the base down, put the Scope on it, and your ready to go.

Yes there are other things you will learn as you go: Cool-down time, better bearing action etc. But straight out of the box the Dob is pretty well ready to use.

Sooooo simple

dhumpie · #11 19-06-2007, 01:08 PM

Get the 10" GSO dob from Andrew's period (to Brissie it only cost about $650 plus postage). You won't regret it. I find the 10" straddles the price range and portability just nicely. The 10" fits easily in my Hyundai Excel Sprint with the seat down. I don't think the 12" would fit in. Also I find I can carry the whole setup (yup tube plus mount) for short distances although I would not recommend that you do that often

Darren

rmcpb (Rob) · #12 19-06-2007, 02:35 PM

10" dob is one of the best around. Lots of aperture but still VERY portable. Good choice.

luka · #13 19-06-2007, 04:20 PM

Make sure you get one with Crayford focuser.

janoskiss (Steve H) · #14 19-06-2007, 04:52 PM

...one with 10:1 microfocus.

Jupiter · #15 19-06-2007, 05:12 PM

I bought a 10" dob about a year ago from recommendations on here, it hasn't dissappointed me yet, if I had my time again I would've bought a 12" though, but thats me and what I know now.
I went crazy at first and used it all the time, got sick of it during summer but now winter is here and those cold frosty nights are back, I'm out in the yard again, go figure.

BTW this website is a goldmine of info.

Tannehill · #16 19-06-2007, 05:17 PM

I think the Bintel GSO dob now comes standard with the CRayford. At least the 12" I bought in April did...

The 10:1 is available as an add-on if you like. The f5 does make for a somewhat touchy focus, I'll admit, and were I to keep this more than a year I would upgrade to the finer control focuser.

scott

ballaratdragons (Ken) · #17 19-06-2007, 05:29 PM

Quote:

Originally Posted by Tannehill

I think the Bintel GSO dob now comes standard with the CRayford. At least the 12" I bought in April did...

You can order all the sizes of GS dobs with or without the Crayford Focuser.

I certainly agree that a Crayford is a 'must' on any scope.

GazzMeister · #18 19-06-2007, 06:26 PM

Well, I post a simple message and go to work expecting 1 or 2 replies and then I get home and look at the response!

I tried a few American forums before i found IIS and they were reluctant (to say the least) to help someone with no idea. I'm now thinking of a 10 or 12inch mail order as there's nothing around Canberra that I can pick up. I usually keep my current scope in my bedroom and we've got 4 stairs from the porch to the ground, but I'm only 27 and fairly fit so I guess I'll go for the 12. I really need to go to a CAS meeting and learn how to collimate

. I'm sure, as you all say, it's not that hard and once I do it a few times it'll become second nature. Is there anything you can easily break while collimating? Or can it all be re-done if you stuff it up big time?

Thanks again for all the help. I think I need someone to just slap me in the face and take my money and just buy me a good telescope

Solanum · #19 19-06-2007, 08:41 PM

I bought a 10" GSO dob from Andrews a few months back and it's been great. Postage from Andrews to Mildura was pretty cheap. I'd phone both and get a quote for the same spec (including focusser and EPs, for instance I think Andrews usually come with more EPs) as all the kit is identical.

My 10" once assembled approaches 30kg. I use a trolley to shift it around ($40 from Bunnings), with a couple of straps and an old cushion. The 12" will be fair bit heavier.

I've found that so far I've seen everything I could wish to with the 10", though you'll see more with the 12", so if you're feeling strong....

Nevyn · #20 20-06-2007, 12:34 AM

Thanks for asking the question GazzMeister!
I've been looking at all these different Dob's myself and wasn't far off posting the same. I have settled on this one https://www.bintelshop.com.au/Product.aspx?ID=6993 because it seems to have the finishing touches eg. "New models have been upgraded and now include 10:1 fine focus Crayford focuser and Correct Image Right Angle Finderscope"

Cheers Brad.