First purchase advice

[StutzJr]

Hi folks (first post here and all that)..

I've been interested in purchasing a decent telescope for quite some time. I have a workmate who suggested I pay a visit to Bintel as I'm led to believe they are the people to see in the Melbourne area. I've looked into their website and done some reading over the last few days. I'm keen to get a dobsonian telescope but I don't want to pay too much at this stage as I'm also planning an upcoming overseas trip. I'd like to explain my expectations and ask for some advice about the options.
I have a trusty old soviet TYPCNT-3 20x50 extending refractor "tourist 3" spotting scope which my dad bought for me when I was little. I take it out from time to time to view the moon and I have once been able to just make out the ∅ shape of Saturn. I'd like to be able to see somewhat better than this as a start.
At this point I set my absolute upper limit at $500 for a ready to go setup with no extra costs for accessories. I'm led to believe that I might be just able to squeeze in an 8" dob with that, but I wouldn't have much left over. My initial thoughts however are to perhaps start smaller than this now, and then if I'm really keen I can go for my preference of a 10 or 12 inch collapsible dob a few more years down the track when I can afford it.
So I'm currently looking at a few alternatives in the range of 6 inch, 5 inch and even the 100 mm tabletop dobsonian units. I'm not kidding either. I figure if I can get a good quality smaller unit, maybe later upgrade the finderscope and eyepieces, it would be better than getting a low end 8 inch unit and have no budget left for accessories. Does that make sense?
So, if I was to simply get a 100 mm dob, would I be able to see a marked improvement over my 20x50 refractor? Would I be able to get better eyepieces later that I can take with me to a future scope?
If I was to look at the heritage 5 inch model, would I have big issues with background light because the secondary mirror is so exposed?

Any comments or suggestions would be greatly appreciated!
cheers

[StutzJr]

I should point out that my primary interest is viewing planets and the moon, at this stage I'm aiming for a purchase in about June-July, or a layby toward that.

[Scorpius51 (John)]

If you are aiming to purchase no earlier than June, then use that time to not only save the $s, but to go to an observing night with the local astronomy group.

Give yourself the best opportunity to look through several scopes at the night sky before you purchase one. You will not regret trying before you buy, but you will regret buying a scope that you have no idea of what it can do, and it doesn't perform as you expect.

Others with more experience will advise you on the other issues you have raised.

All the best!

Cheers
John

[StutzJr]

Thanks John,
I might pay the Geelong guys a visit on Friday night for a look.

I'm still interested yo hear some comments on my questions. I also haven't ruled out looking at a larger refractor like this one: http://www.bintel.com.au/Telescopes/...oductview.aspx

so many choices!

[Scorpius51 (John)]

An 8" Dob is a great way to start, but if you're financially constrained, then a 6" is allowing you to have some change for bits 'n pieces. But, you really don't need all that much extra to enjoy visual observing. You will get a few reasonable Plossl eyepieces with a Dob purchase. Collimation can be done without an expensive laser. All your sky software & charts that will get you going can be obtained freely off the web.

If you go to 100mm, it will double the aperture from your 50mm, but quadruple the light-gathering. If you get the 70mm refractor, it will increase your aperture by 40%, but nearly double your light-gathering.

Personally, I wouldn't go below 6" for my primary scope, but if it's something you would keep when you upgrade, as a grab & go, then maybe!

You can always get better eyepieces and use them with an upgrade scope. Don't get too fixated on accessories, you can do some very rewarding visual observing without too many extras.

Cheers
John

[barx1963 (Malcolm)]

I am not a fan of table top dobs, to my mind 6" is the minimum. I know some have them and like them, but I am not convinced.

Malcolm

PS good to see more Geelong region observers!! Try to make it up to a Snake Valley Club Nioght or the Camp next November!

[StutzJr]

Cheers John, I appreciate your thoughtful answers and suggestions.

I'm stating to lean toward looking for a quality unit that is the best performer for planet viewing in my price range. I keep going back to this one Skywatcher 6" F/8 - hopefully a good balance of price, flexibility and quality? yt video The only issue here is the tradeoff between portability and optimal planet viewing in terms of focal length - is that right?

If I can get along to a local club meeting I'll ask to look at a 70 mm refractor and a few reflectors up to 6" but I really don't want to look at anything bigger, in case I get sucked in to spending more!

Malcolm- sounds like an idea.. If I do get more into this I might be heading over anakie way to find some dark viewing spots.

cheers,
Richard

[StutzJr]

So I finally got back up to bintel yesterday and picked up my Skywatcher 6" dobsonian scope. I'm very happy with the quality of the product and what I got for the price. The instructions were clear and informative and the unit was pretty easy to put together. The scope seemed pretty much in collimation straight out of the sealed box. The unit came with two eyepieces, marked "super 10 mm" and "super 25 wide angle long eye relief". The finderscope is a fixed 6x30 on a simple dovetail mount locking ring with easy alignment screws. The focuser assembly is solid and simple to operate, and can accept either 1.25" or 2" eyepieces. The provided eyepieces look like pretty basic generic quality but worked well enough. The box for the base was marked as 12 kg and the box for the scope was marked as 7 kg. The scope box fits ok on the back seat of my car. I haven't tried putting the constructed base in the boot yet but I'm pretty sure it will fit ok.
I finally got it out for a brief look late last night after the rain stopped and before it clouded over again. I found Saturn in under 2 minutes using the finder scope that I'd just roughly aligned by eye and the 25 mm eyepiece. I switched to the 10 mm eyepiece and had to refocus a little. Nice! I could clearly see the little ball with ring around it, unmistakable. Pretty sharp & bright and far superior to what I could make out with my old 20x50 refractor, though I couldn't make out much definition on this first attempt. I can see myself wanting a 2- or 3- x barlow and/or 6mm planetary eyepiece soon enough.. I had to move the base to keep aligned after about a minute due to rotation but the whole thing sure stays nice and still when required. Nice pleasing starfields with the 25 mm EP but I didn't really spend much time trying to find anything in particular.
I notice that I'll need to practise using the EP's or get some rubber eyeguards as I have a left dominant eye and cannot close my left eye independent of the right - makes using the finder scope a bit inconvenient for me - I have to either squint with my head right against the tube or go around the other side. I'm going to borrow a mate's red dot finder and see if that's any easier for me.
So there we have it. I'm looking forward to spending some time getting to know this one while I learn the ropes. cheers!

[ZeroID (Brent)]

Good report Richard. Just be careful about the EP selections you make. A 6mm will be pushing the 'seeing' on a 6" . Planetary viewing is affected by atmospherics.
Ask the experts and they will advise.

[jjjnettie (Jeanette)]

Bintel have quite good budget barlows. I have the GSO version of this one and can highly recommend it. Using this barlow with your 10mm eyepiece should satisfy your planetary lusts.
http://www.bintel.com.au/Eyepieces-a...oductview.aspx

[StutzJr]

So I'm just back in from my second night of trying out my new scope.
Some nice views of Jupiter and the Moon earlier on. I was able to just make out some of the layers on Jupiter and saw at least 3 moons clearly. The Moon was stunning as to be expected. Later on I was able to look at Saturn again, as per below I had a slightly better setup this time and was barely able to make out the cassini division in the rings if I really tried. I now have my scope finder aligned nicely and am more confident in the correct collimation of the scope, If I go in and out of focus on a point I can see symmetrical diffraction rings around the point. (the scope didn't come with any collimation tools - but clearly didn't need any up front).
I showed my workmate the two eyepieces and today straight away he pointed out what I thought was a poorly moulded thread was actually the rubber eye guard folded back around the barrel of the EP - d'oh! So much easier viewing when I use the eyepiece properly haha!
Thankfully he's offered to loan me a couple of eyepieces for me to try for a few weeks so that 1. I can have a chance to compare my EP's to others of the same spec, different brand to see the difference like for like, and 2. so I can try some other focal length EP's and get an idea of what I might want to buy myself later.
When I lock the tension control handle it is possible to lift the base with the scope attached but I wouldn't want to carry it too far like that. Luckily I can set up under my back patio early in the evening and when I come out later to start it's already cooled/acclimatised and ready to go.

[ZeroID (Brent)]

Young padawan learns fast ... excellent !!

I think one of Jupiters moons was hiding behind the planet last night.

My favourite EPs are a couple of GSO 15 & 20mm Superviews. Quite reasonable cost and good value for the $$ ( about $50 new each at a guess ).
They give good eye releif and nice wide views with pretty good sharpness to the edges.

[brian nordstrom (As avatar)]

Good choice of a scope you made here , hope you get to use it lots .
You can not go wrong for $320 , can you ? Enjoy .
Oh yes , great report by the way . .
Brian.