Hi All.

gpb (Chris) · #1 26-01-2011, 03:28 PM

G'day all, finally I'm about to purchase my very first telescope. I have a budget of $3K and currently looking at purchasing the Celestron Nexstar 8SE http://www.celestron.com/c3/product....=13&ProdID=416 including a few other accessories.

I'm really excited about this new 'toy' and really can't wait, but I have this lingering thought in my head whether I am making the right decision on whether it is the right telescope. Reading though this forum there are many Dob users and they say that the aperture is what keeps them with their Dob. OK fair enough, can someone tell me if I'm making the right decision and any SCT users out there, how happy are you with your telescope?

Later on in the year I would like to do astrophotography, so would the 8SE be sufficient?

This website has heaps of knowledge to the point it is confusing me as to what to purchase.

Any suggestions?

barx1963 (Malcolm) · #2 26-01-2011, 03:46 PM

Hi Chris welcome to IIS

Congtratulations on being in a position to get a really nice scope. There are many pros and cons to any telescope purchase simply because there is no such thing as a perfect alround scope. Everything is a compromise.
I am a dob user and don't use go to or push to technology, so I am probably biased. However my usual point is that if you go to any star party and have a look at what people are using, by and large the majority of visual observers are using dobs. Simple as that.
The 8SE involves sacrificing aperture for the convenience of go to and if you really need to have go to then go for it. To me, I enjoy the hunt!
For your budget you can have a 12" dob with twice the light grasp of the 8SE and still have $2k left for accessories, especially good eyepieces, atlases and dew heaters.
Your other point is astrophotography. This is an alt az mount, so is really only suitable for bright planets and the moon. Deep space will require (usually) an equatorial mount. There may be a way to wedge this mount, but I am not sure.

Malcolm

manu_78 · #3 26-01-2011, 04:08 PM

hi chris,

i was also looking at buying the celestron or the meade lightswitch model, however, once i did a bit more research and got talking to some people who new (heaps) more than me, i went for a dobsonian. The thing that got me was the fact that its the light gathering power which is most important for what i want to do with the scope - but a dobsonian isnt going to be much good for photography. The price difference is massive between the two ifferent types of scopes - dobsonians are much cheaper, which leaves me heaps of money to buy eyepieces and accessories etc. I was also put off by the fact that overseas the celestron and meade were only about 40% of Australian prices, even though we have a high exchange rate at the moment. I am very happy with my dobsonian, but i am not into the photography side of things (yet) i am happy just observing the night sky at the moment.

gpb (Chris) · #4 26-01-2011, 05:28 PM

Thanks Barx & Manu, you guys have suddenly put my mind in a spin and I'm panicking because I'm totally lost. I think the reason for this is because I've had no 'hands on' experience with any telescope to draw a conclusion on what really suits me.

Does anyone have any photo comparisons between the Dob & the SC?

Barx, you talk about the alt az mount & deep space will require an equitorial mount, can you explain or where can I find what this all means?

Manu, after viewing overseas prices versus Aussie prices I was shocked but I have found Andrew's easier on the pocket than some others in Australia.

I have another question, I see there are 12" Dobs with Goto, will this type of unit still allow me to use it manual mode, i.e allowing me to go up/down & side to side when I'm not in auto mode?

Will the 12" Dob with Goto still give me flexibility for astrophotography?

Dob users, what are the disadvantages about your telescope?

barx1963 (Malcolm) · #5 26-01-2011, 05:45 PM

Chris
It's important top take your time, it's your hard earned cash. One of the best ideas is to get along to an observing or club night or a Star Party and see the various scopes. As long as you are polite most observers are happy to let you look through the scopes.
An alt az mount is one that simply turns and goes up and down while an equatorial mount is one that has an axis aligned to the polar axis of the earth. For astro photography you need to keep the same field in the view without rotation for long periods of time. DSO's can involved hours of exposures as they are very faint. If you try and photograph through a scope mounted on an alt az mount, the field will turn giving you streaks rather than pinpoint stars. Because the Field of View rotates at the same rate as the earth turns with an equatorial mount, this amkes them suitable for imaging. (hope I have explained this OK, )
A dob is simply a variation of alt az mount, and so is not suitable for imaging except for short exposures (moon and bright planet). Of course the scope can be taken of the dob mount and put on an equatorial mount.
Yes there are dobs with go to and yes they can be used in manual mode. IMHO if I was going to go for a go to, I would choose one of these rather than a equatorial mount as it eliminates the need for polar alignment and still gives large aperture for the $$$.
Disadvantages of a dob. Probably the main one vis a vis a small scope like the 8SE is bulk. If you go solid tube the are big units and you need a bit of physical work to carry them. Of course there are collapsible and truss tube models that elliminate much of that issue.
I have a 12" solid tube dob and if I didn't have a wagon, I would struggle to transport it to star parties etc.
One other possible disadvantage against the 8SE is you have to learn to collimate. Thats certainly not hard to do and after the first 3/4 times you can do it in a couple oif minutes.

Hope all this helps

Malcolm

gpb (Chris) · #6 26-01-2011, 07:08 PM

I just finished reading this http://www.opticsplanet.net/how-to-buy-a-telescope.html before I read your post Malcolm and you have described it perfectly mate.

Gee, I have really swayed to the Dob side you guys have really opened my eyes, thanks. You know, you can read a lot of stuff on the internet but the most valuable information comes from a place like this with people willing to help.

I'll let you guys know what I get.

barx1963 (Malcolm) · #7 26-01-2011, 07:24 PM

Good luck with your decision mate. The most important thing is that you are happy with the decision you make and taht you get enjoyment out of the scope.

seeker372011 (Narayan) · #8 27-01-2011, 06:33 PM

look through a scope before you buy if you can
get to your local astronomy club and look through several
You may find that the much cheaper dob blows the more expensive scopes away on some objects

Suzy · #9 27-01-2011, 08:29 PM

Hi Chris,

When I first joined here, my first and most curious question was "why do you people have some many scopes" (as listed on signatures), so I started a thread. The response from everyone is that each telescope does a different job. One for quick grab 'n' go (portablility/small/easy to set up), one for visual (the big one/aka dob), one for photography ($$$$). And of course everyone has got their trusted binocular.

The best advice I could give you is, is to hold off pouring a lot of money like $3000 when you're unsure of what field it is you want to pursue. Astrophotography from what I've come to understand is a money pit, and requires much dedication. I first started out with a 6" dob (apperture + affordability). Within six months I knew what I wanted to do, so I sold my 6" and upgraded to a 10" and I've never looked back. I think it's easier to upgrade up as you progress, than to spend a lot of money that may be wasted. If you want to do both (visual+photography), I think you may be better off going for the dob first (lots of apperture) and then as you learn more, you will have more experience as to what money to pour into astrophotograpy gear with a another dedicated scope.

As for pluses for a dob....

The big plus for dobs (apart from aperture & affordability) is the fact that they take no time to set up. Often a beginners frustration, having to take an hour to set up, then dreaded clouds usually roll in. Beginners (I'd be guilty of it) just want to plonk and look and get a quick wow rush factor. Also, if I only want a quick session (say one hour), I can do that, eliminating set up time. Many people lose motivation with the sheer fact that they have to spend so much time setting up. I have no "go to" on my dob either - I like the challenge of the hunt (it's very rewarding).

My 10" dob just fits in the boot of my Holden Commodore and Mitsubishi Magna, with the base strapped in on the back seat. Big enough, yet, just portable. The tube measures 1200mm. Trust me, you'll get a big wow factor with this. And especially if you are in suburbia and want to see as much as you can, 10" is the way to go.

Find yourself first, enjoy, then go from there. Your money will be well spent then, when the time comes.

barx1963 (Malcolm) · #10 28-01-2011, 12:39 AM

Beautifully put Suzy!

ZeroID (Brent) · #11 28-01-2011, 08:49 AM

Quote:

Originally Posted by barx1963

Beautifully put Suzy!

Agreed, bang on good advice for sure.

Suzy · #12 28-01-2011, 10:42 AM

Thanks for the wonderful support, Malcolm and Brent, you'll are very kind.

gpb (Chris) · #13 28-01-2011, 12:16 PM

Hi Suzy, as the others have stated it was a very good piece of advice you posted and thanks. If I wasn't sold on a Dob before, I am know.

I think the set up factor you described is a big plus and it's something I never knew.

astroron (Ron) · #14 28-01-2011, 01:59 PM

Suzy, What a well thought reply to Chris's enquirey

Chris, with all that Good Advise from Suzy, Malcolm, Brent and Narayan, you cannot go wrong in investing in a 10" dob, you will get the "Best Bang for Buck" and a lot off enjoyment

Cheers

gpb (Chris) · #15 01-02-2011, 02:25 PM

After many hours spent researching, mind you the most valuable information was on here, I would like everyone to know that I am a proud owner of 12" GSO Dob. I originally said I was going to take a few months but once I visited Bintel I walked away satisfied. The information that I gathered on here reading through various threads really helped and I understood the terminolgy and what it meant.

Set up was pretty easy but I will have to use barx1963's trolley mod idea to help me to get this thing in & out of the house - thanks Malcolm. I bought myself a laser collimator which made life easy, well I don't know any other way now. I mucked around for several hours learning the Dob and the different eyepieces. It didn't take me long to work what needed to go where and when. My wife wanted to look through it and her very first word was "Wow", she descibed the night sky like diamonds in space.

Now it's time to understand the difference ep's and what brands are suitable for my Dob.