This is so Brain numbing - beginner first scope choice

[dclnmurray (Dave Murray)]

Hi All

Been reading lots and just so confused.
First time I am venturing into Astronomy after my Brother in Law showed me stuff through his 12" Dob
http://calgary.rasc.ca/telescope_mak...R_gussie-1.jpg

So I am hooked. Have about 800-900 budget.

The three areas and the scopes I have looked at are

1: Computerised
NexStar 130SLT

2: Dobsonian
10" skywatcher

3: Mounted reflector
200mm Skywatcher on EQ5 mount.

Not interested in planets much but rather view NGC's and M DSO. Not Interested in photography, well not yet anyway.
Interested in joining a group so transporting scope is required and live in southern Brisbane areas.

I know it really is a loaded question but can anyone provide guidance?
Also if anyone can recommend a good group to join I would be appreciated.

cheers

Dave

[multiweb (Marc)]

Choice 1 for me. I started like you not really knowing where to go and 2 years later I'm still using the same scope for imaging which is the Celestron Nextstar 130 SLT.

[dpastern (Dave Pastern)]

OK - you're interested in DSOs, that means aperture rules. In all honesty, that rules out refractors. Not interested in photography (at least yet) - no real need for a German Equatorial mount then. GOTO is nice, but not strictly necessary. The Nexstar is only 6" - it'll struggle seeing some DSOs imho, especially if from a light polluted city environment. It will making finding them easier though.

I'd personally go the Dob myself. Andrews has some specials at the moment too:

http://www.andrewscom.com.au/site-section-10.htm

scroll down till you find the section named:

Genuine Skywatcher collapsible flex-tube

The 10" is $899. I'm not sure if it includes eyepieces or not, but you could always pick a few cheapies up that'll last you until you can afford better. I'd recommend the:

GSO 15mm plossl
Andrews 30mm 82º UWA

I'm not too sure what to advise for higher magnifications, the Andrews 4mm plossl that I have isn't very good imho. Maybe the GSO ones are better quality.

Hope this helps.

Dave

edit: get a good UHC filter for DSOs as well down the track

[Astro78]

50% brighter images on the 10" would be the clincher - but. If you consider the time spent tracking an object under high power with the dob vs. an object that will stay in field with a cheap motor on an eq5. Your likely to see more i reckon with the EQ and slightly smaller scope.

Just being able to sit there and study a centred object, to me is really valuable

[Screwdriverone (Chris)]

Hi Dave,

I agree with David, 10" collapsible Skywatcher from Andrews for $899 (or York Optical for same price - become an IIS VIP for free).

Biggest mirror of the three, collapsible front end (I have a 12" version) makes it VERY portable and as a first scope, comparing it to the views you saw through your Brother In Law's bigger one won't be disappointing for you when you shell out $900 for a smaller scope.

EQ platforms are great but fiddly as a first time scope and without goto are frustrating at times to find things. Dobsonian mounts are the best choice for first time users (I bought an EQ2 - SW135 first and then a 12" Dobsonian next) and I wish I had done it the other way around.

Take a look in at York Optical in Brisbane and see if they will give you the 10" collapsible for $899 (VIP price) as you are IIS member now and you will never regret the choice. I think they will honour the price match of Andrews Comms or at least give it to you for the price you would get it for if you became a VIP with them anyway.

Good luck with the decision.

Cheers

Chris

[DavidU (Dave)]

10" dob does it for me too.

[Wavytone]

In your case buy the biggest aperture dob you can find within your budget - secondhand should also be considered because you can have the mirrors recoated later.

Decent eyepieces can come later when you have saved a bit more, be prepared to spent upwards of $500 on 2-3 of these.

[barx1963 (Malcolm)]

Close to the city you will have light pollution so aperture rules, get the 10". Learn to star hop and you can find stuff to your hearts content. The 130mm scope is a great unit but no point in a go to to find stuff if you cannot see them when you get there. The 10" will give you enough light grasp to see plenty.

[ngcles]

Hi Dave,

Originally Posted by Astro78

50% brighter images on the 10" would be the clincher - but. If you consider the time spent tracking an object under high power with the dob vs. an object that will stay in field with a cheap motor on an eq5. Your likely to see more i reckon with the EQ and slightly smaller scope.

Just being able to sit there and study a centred object, to me is really valuable

True, it is quite valuable to have a drive but 50% brighter? Try 4x brighter in the 10"! In rough terms we're comparing a 5" and a 10" yes? The light-gathering power is proportional to the square of the diameter of the aperture.

5 x 5 = 25

10 x 10 = 100.

130 mm is not a "slightly smaller 'scope" than 254mm -- not today, not tomorrow, not until the laws of physics change.

If you are interested in visual observing of DSOs, the view you will get with 130mm aperture will certainly be disappointing after looking through a 12". The view will be a little more than 1/6th as bright -- 130mm -v- 305mm. Yes with the 130 you will get goto which is very nice and a drive also but the number of DSO's visible will be dramatically smaller than the 10" will show and much less detail and brightness.

In the end it boils down to what you value. A brighter much more detailed image or the convenience of GOTO and a drive. But beware, 1/2 the aperture does not equate to 1/2 the light -- it's 1/4 the light

If you are going to observe deep sky, aperture rules! But also bear in mind portability. The 10" will take a fair bit more lugging around and storage space.


Best,

Les D

[circumpolar (Matt)]

Originally Posted by dclnmurray

Not interested in planets much but rather view NGC's and M DSO. Not Interested in photography, well not yet anyway.

This suggests you need a dob.
Plain and simple.The most bang for your buck. Most NEW dobs come with ep's and a finder scope so you can start observing straight away.

Note: You WILL NEED a collimation tool! and you will need to learn how to use it. Plenty of advise here on the forums.

[stephenb (Stephen)]

Dave, go the 10" Dob for all the reasons outlined by the previous members. Aperture, aperture, aperture You will not regret it.

GOTO is great for a beginner, and nothing wrong with it, but you will learn more by locating the obects yourself. What you are paying for in the GOTO feature, you are losing in aperture. With a Dob, what you are paying for in the aperture, you are losing in not haveing a GOTO feature or the ability to track with an equatorial mount. It's all trade-offs.

Get yourself a planisphere, a simple star atlas, and I would suggest a Telrad for your next purchase (approximately $79 at BinTel)

And get hooked up with a local astronomical club in your area - that's where the wealth of information and experience is.

Good luck,

Stephen.

[dclnmurray (Dave Murray)]

Hi All

Thanks for the info and with further reading I have come down to a choice of two. An 8" or a 10" dob.

Spoke to a chap at Andrews communications and he recommended the Guan Sheng 8" super deluxe at $499. With the five eyepieces and extras this is probably a good start for me. However my budget does go to the 10". So for traveling will the 10" fit in the boot of my Ford Focus?
This is what will determine the purchase.

Might check out the viewing night at Brisbane Planetarium this Saturday and see what members have.

Bye for now.

Dave

[Blackant (Ant)]

Originally Posted by dclnmurray

So for traveling will the 10" fit in the boot of my Ford Focus?
This is what will determine the purchase.

Dave

Hi Dave,

I'm not sure what a Ford Focus is but I've got a 1997 Hyundai Excel and an 8" Dob. It JUST fits in the boot of my car, with the base next to it, I'm glad I didn't end up getting a 10" Dob cause there is no way I could fit it into the car except on the backseat which meant the kids and my long suffering wife would have to stay at home

I've been really happy with it performance wise, it's pretty well blown my mind with what I can see with it

Bare in mind though I have dark skies (I live in a small town about 40 kms south of Hobart) and I haven't looked through any bigger telescopes yet
Might be a good thing actually, I don't know what I'm missing and wouldn't be able to transport one anyway

Kind regards

Ant

[stephenb (Stephen)]

Originally Posted by dclnmurray

...Spoke to a chap at Andrews communications and he recommended the Guan Sheng 8" super deluxe at $499. With the five eyepieces and extras this is probably a good start for me. However my budget does go to the 10". So for traveling will the 10" fit in the boot of my Ford Focus? ...

Dave, ring Andrews back and ask them for the dimensions of both sizes. You already know the tube diameters (add approximately 1- 1.5 inches), but you need the lengths.

You can't go wrong with a GSO Dob, by the way. Nice choice

[Astro78]

Originally Posted by ngcles

True, it is quite valuable to have a drive but 50% brighter? Try 4x brighter in the 10"! In rough terms we're comparing a 5" and a 10" yes?

For the record I was commenting on the 8" vs 10". 50% brighter is correct thanks Les

[ngcles]

Hi Astro 78,

Originally Posted by Astro78

For the record I was commenting on the 8" vs 10". 50% brighter is correct thanks Les

My misinterpretation mate -- thought you were commenting on -v- the 5". I've re-read your original post and I dunno how I got that mixed up -- my fault.

Correct -- 10" -v- 8" is a 56% brighter image.


Best,

Les D

[space oddity]

Other things to consider:-protection for scope will affect fit in car.You will need a couple of very useful if not essential accessories eg telrad, red torch,collimation tool, eyepieces,planesphere, observers guides, warm clothes, maybe an argo navis?
Personally,I reckon a second hand outfit will get you a large amount of bang for the buck.Rule of thumb- the other bits and pieces will set you back as much as the telescope itself.
The most important "accessory" .........DARK SKIES

[barx1963 (Malcolm)]

If speaking to Andrews ask about dimensions of the MOUNT as well as the tube. The 10" will have a fairly large base and is quite high. On my 12" the base won't go in through the door of my Astra Wagon, so chances are a 10" base will need to go through the hatch (if you have one) of your Focus.
And I agree with Stephen, can't go wrong with GSO Dob.

[dclnmurray (Dave Murray)]

Hi all

Me again. Just one more question as I definately am buying an 8" or 10" dob. I gave my local hobby (telescope) store an option to offer a similar setup to what Andrews GS-880 is but his email although polite was quite firm in stating he will not compete against inferior products. He mentioned the Skywatcher range has Pyrex and the GSO has Glass for the mirror. In checking around I don't seem to find any evidence of this being an issue however can anyone shed any ore light on this?

In fact checking around there are many comments about the GSO optics being quite good.

The other fact is as a beginner does this really become a concern?

EDIT: just found this article and answers the question from at least one source
http://www.skyandtelescope.com/howto...tml?page=2&c=y


cheers

Dave

[shane.mcneil]

Hi Dave

Both Skywatcher and GSO telescopes are glass. Skywatcher is Pyrex glass. GSO is BK7 glass. Pyrex cools faster than BK7 but aside from that there is not much difference at this size. If you go above 10" then pyrex is recommended.

GSO's come with a fan which helps cool the mirror faster anyway. My GSO has a right angle viewer plus a 10:1 focuser which I like. Everyone said that either brand is good so I just picked one and went with it. I would like to have seen them though. I have heard that Skywatcher is a bit better build quality?? Don't know though.

Hope that helps.

Shane