help with old 8" dobsonian

[vonm]

hi guys,

So I just picked up an old 8" dobsonian for $100 today. I've never even looked through a telescope before, so a complete newbie at this.

From what I can tell, it's all intact, except there are no eye pieces. Primary mirror and tube itself looks a bit dusty, which I suppose I can give a clean. Components are mounted on Parks branded mount, which apparently is a good brand. There's also some sort of laser pointer scope.

So my question is, where to from here? Can I just buy any eye pieces, put it in and start looking. What would you recommend? What other accessories do I need? Finally, was it a good buy at $100?

Thanks,

Vonm

[dannat]

a steal at 100 provided the mirror is ok
- you could prob start with some cheap ep's from bintel , or advertise a wanted ad here for some starter ep's
- does the focuser have its 1.25" adapter?

[GraemeT]

Welcome to IIS Vaughn:welcome:
I'm not familiar with Parks scopes but it's hard to go wrong with $100. Yes, just grab a couple of eyepieces, 1.25" plossls will do the trick, there should be some advertised in the IIS classifieds, and start viewing. THEN, ask as many questions as come to mind. You shouldn't need to pay more than $30 each for a 10 and a 20mm,and start with easy targets like the moon. It's new moon on tuesday so the moon will be a thin crescent and easy to see without a moon filter. ENJOY!!!

[raymo]

From what I can see, it was a good buy. A couple of budget eyepieces to
get you started won't cost much. I suggest that you view a video on mirror cleaning before tackling the job; you don't want to stuff up a
good mirror. If it is only a bit dusty, I wouldn't bother cleaning it for now.
A mirror can be quite bad before it affects your viewing much.
raymo

[louie_the_fly]

:gday:

Before you clean the optics read up on how to do it. There's an article on the IIS projects page http://www.iceinspace.com.au/63-345-0-0-1-0.html (http://www.iceinspace.com.au/projects.html)

If done the wrong way you can do some serious damage.

Enjoy your new scope.

[barx1963]

Vaughn
At $100 hard to go wrong. Looks more like a Telrad rather than a laser I think?
With the mirror if it is just dust, a simple rinse with water then with demineralised water will get most of it off.
Coatings on mirrors are actually quite robust, but still take care. If it is old the coating may not be very good in which case washing may damage the reflective surface.

Malcolm

[vonm]

wow..thanks all for the quick replies!

I guess I should hold off on cleaning the mirror. Should be ok to give the tube a wipe to clean off the dust.

Malcolm, you are correct, it is a tetrad, after googling telrad, it looks exactly the same.

So I'm thinking a 10mm and 20mm plessl and moon filter should do the trick.
Do I need a barlow? how about a collimator?

Just hoping the mirror is still good.

Thanks all.

Vaughn

[raymo]

I suggest that you get a 10mm and a 25mm, because 25 will give a wider low power view than a 20, and the barlow will give you effectively four
eyepieces, whereas with a 20 it becomes a 10 which you already have, so you effectively only have three eyepieces. If you like low power sky
sweeping, you could even get a 30mm.
raymo

[barx1963]

Good advice from everyone. With EPs, just a 10mm and 25mm plossl is enough to get started. I had a GSO/Bintel 32mm plossl and it was OK as a really wide field EP to help find stuff, but it had fairly significant field curvature that I found a bit uncomfortable. The 30mm Superview (assuming you can use 2" eyepieces) is a bit better but at $49 is worth 1/2 as much as your scope. I have one that I use in my little 8" and I like it a lot, quite often pop it in the 20" if I am after really low power views.
Personally I would avoid barlows unless you can really justify a use for one. I have had a couple and always preferred the view from stand alone EPs and in all the camps I have been to I have never seen a visual guy use one.
With collimators it is easy to spend much more than you scope is worth. Here is a very good guide that I have used http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide .htm which outlines the basics of collimnation using simple tools.

Malcolm

[ZeroID]

15 and 20mm GSO Superviews and a 2 x Barlow. the 20 SV gives about the same fov as a 25mm Plossl. With that combo you'll have 20-15-10 & 7.5, a nice useful range for reasonable prices. I started with the two SV's and they are still my most used EP's.
My first scope only cost $50 and the EPs totalled about double that, still a good buy. :thumbsup:
And although I tend to agree with Malcolms comment re Barlows above it's still handy and sometimes is usefull to unscrew the lens and use it as an extender. And it will give you some options to consider for your next EP purchase .. :D

[brian nordstrom]

:) Hi Vonm and welcome to IIS , great scope you have there and the Parks mirror cell is an oldie but a goodie from yesteryear, very good gear.
On the SV eyepiece,s the 20mm is very good , I have one and I have done a lot of testing of this against my beautiful TV 19mm Panoptic and it holds up very well , close, almost identical out to 70-75% of the field where the TV is better , perfect to the edge even in my f5.5 sky90 , but in your longer Newtonion it won't be to bad. I would suggest Plossl,s but. for only a little more the SV,s are the ones.

Leave the mirror alone for now. , just collumate it. And enjoy , its a great scope you have.
Brian.

[vonm]

Might try out the 20mm Superview as a first step to make sure the scope is working ok...then who knows from there.
Although, I have seen some Celestron zooms 7.5-22.5mm going for a little bit more. Probably stick with the 20mmSV?

Appreciate all your help so far. Cheers.

[PSALM19.1]

Hi Vaughan...ah where did you grab an 8" dob for that price? Wow! I've always had this dream of finding a 12" version in a garage sale for 50 bucks...:rofl:

[vonm]

My old friend gumtree. Once in a while they do come up but you have to be quick because at those prices they're quickly snapped up.

[Pinwheel]

Better learn fast how to properly clean the Primary & secondary BUTTTT! You will upset the optic alignment so read up on COLLIMATION too!
Great win though!:thumbsup:

[Brycepj]

Great buying please don't tell my missus though like a lot of us we have easily spent 10-20 times more ( and the rest for some).
Eye pieces I would get an orion 28mm if you have a 2" focuser it's what I started with. But others here would have better knowledge.
Wouldn't worry about cleaning mirrors just yet