Okay - Dob it is (maybe)...

taxman (Matt) · #1 04-06-2008, 04:32 PM

After trying to "save" money by getting a reasonably good 90mm refractor on a wobbly eq2 mount (unless you want to buy it - then it's awesome) I pretty much nipped my burgeoning interest in the stars in the bud.

I then got a spotting scope for my office (55mm Olivon - seems unbelievably good to my inexperienced eye) as I work late most nights until 7 or 8 at night and a quick session with the moon perks me up before I go home.

Then, a couple of weeks ago, I took my little spotting scope up to Mt Cootha with the kids and got a look at Jupiter through it. We saw two cloud bands and 4 pinprick moons.

Bang - I'm hooked again.

I read elsewhere on this forum about a chinese manufacturer selling 5" apos for ~$800, emailed him and almost made my mind up about a 6" short tube achro.

Today, I went to the Bintel website and then called Don who has offered me a pretty good deal on an 8" dob +freight+6mm eyepiece+cheshire collimator. I also like the idea of a day or two for delivery, rather than waiting for 40 days.

Luckily I have an indulgent partner who actively wants me to get a telescope, particularly after the kids' experience.

But, I am by nature tight and need some advice that the dob is the way to go before I can take the plunge. Any comments?

Starkler (Geoff) · #2 04-06-2008, 05:49 PM

Two things to keep in mind:

1: Aperture rules. The more aperture you have, the more light you collect and the more you can see.
2: The cheapest way to get the most aperture is with a dob.

GrahamL · #3 04-06-2008, 07:39 PM

An 8 " is a great size scope and will show you a lot

very intuitive to use and the kids will get the hang of it pretty quick .
A telrad would be a good addition as well and isn't to pricey.
http://www.backyard-astro.com/equipm...ad/telrad.html

good luck

JethroB76 (Jeff) · #4 04-06-2008, 07:54 PM

Get the Dob

Screwdriverone (Chris) · #5 04-06-2008, 10:05 PM

Hey Taxman,

Yep, get the DOB, everyone in your family will be able to drive it and you wont have any issues with polar alignment and heavyish mounts and complicated operations.

Plus, you get a bucket full of light for the price. I was itching to get a SW880 from Andrews (10 inch Skywatcher DOB) for $399 as a runout model before they all sold out, so I am very envious.....

Now, I have my eye on a 10 inch Meade Lightbridge ($899 from Astro Optical or Bintel) or a Flex Tube Skywatcher 10inch DOB for only $699 from Andrews with free freight. Andrews also have the same type dob as Bintel - GSO Super Deluxe version of the 10" DOB with more bits and pieces and a 10:1 fine crayford focuser (worth $120 alone!) for only $499!!!!

These may give you a couple of options if you havent already checked them out. Sorry to chuck a spanner in the costings if you think you are getting a good deal for the price, by all means stick with what you have already sourced.

Cheers

Chris.

rmcpb (Rob) · #6 05-06-2008, 09:46 AM

The 8" dob is a great workhorse scope that all of your family will be able to drive solo. You will need a cheshire eyepiece to collimate it, a chair, red torch and a star chart and you are away.

Personally I would reconsider the 6mm eyepiece. It is functional, I had one, but you have to nearly glue your eye to the lense to use it. For an 8" a 25mm, 15mm and 9mm eyepiece with a barlow is a good starting range.

Cheers

Solanum · #7 05-06-2008, 10:30 AM

You won't be disappointed with the dob (unless you're planning on astrophotography - then you will). It's a great way to be able to see a huge amount of stuff and they are easy to use (especially with a Telrad or similar). Bear in mind the mount is undriven and whatever you are looking at drifts across your view (pretty quickly at high magnification too). It doesn't take long to get used to 'nudging' the tube in the right direction though.

I agree with Rob about the 6 mm eyepiece (I assume this is in addition to others? The 6 mm on it's own would be useless), the 6 mm standard plossl is awful to use, your eye has to pretty much touch the glass and the eye lens is tiny. Plus, about 50% of nights the seeing will be inadequate for the magnification it provides).

AlexN · #8 05-06-2008, 12:25 PM

Im using an 8" dob and its fantastic, Its my first telescope, and being on a dobsonian mount has made it incredibly easy to pick up.. Simplicity in the mount can really help nurture the early beginnings of astronomy, as you spend less time setting up, and more time gazing at the sky and its many wonders!

as has already been said, but i'll say it again because its important. Aperture rules. the biggest scope you can afford is usually the one you want. Dobs are the cheapest route into big scope land, and hence the way I went, and the way (in my opinion) you should go.

Alex.

ving (David) · #9 05-06-2008, 01:13 PM

one thing to consider...

if you want to image planets, the moon or deep space in the future get a solid tube dob rather than a truss as you can mount a solid tube on an equatorial mount later if you want to (i have done this). check my website for a pic of this.

taxman (Matt) · #10 05-06-2008, 04:49 PM

Thanks everyone for your feedback.

I have ordered the 8 inch dob, and apparently it will be on my doorstep tomorrow. Seems pretty fast from Sydney to Brisbane...

The package I am getting does include a 26mm 2", as well as 15, 9 & 6mm 1.25" eyepieces. I am assuming these are the GSO ones, which seem to be okay at lower mags.

As well as this, I have managed to rescue the parts of a 20mm GSO from the 6 year-old's toybox which I have put back together (it's more than likely had it, though).

I have been reading about paracorr fittings in a particularly feisty thread elsewhere on the forum, but hopefully will have enough for a decent eyepiece (~$200 - maybe a vixen?) in a month or so, and can get away without one (paracorr) for the time being.

As far as focal length for the next eyepiece, what are people's thoughts on this?

I hope I'm not asking too many "newbie" questions!!

JethroB76 (Jeff) · #11 05-06-2008, 05:05 PM

Assuming your soon to be new 8" is F6, you probably won't benefit greatly from a paracorr at all, so you can funnel the $$ into eyepieces if you so wish..

In terms of focal length of the next EP, you've got a good array to begin with; get some experience at the focuser, work out which of the fl's you use the most; your workhorse if you like..though if you're talking Vixen LVWs it'll probably be 13mm or maybe the 17.

Don't rush in though, and if possible get to a club night where you may be able to try some different EPs..also buy secondhand if possible once you've decided what you want.

Starkler (Geoff) · #12 05-06-2008, 05:37 PM

You will want an eyepiece around 12mm for general dso viewing and a 25-32mm for widest field viewing and finding things.

AlexN · #13 05-06-2008, 06:25 PM

i've gone nuts on ep's since i bought my 8 inch. Should update my signature.. I've found a good 12 mm and a good 30mm to be my work horses, the wide for finding and the 12 for getting a bit more up-close and personal. Price of ep's can be scary, but you do get what you pay for. My next will be a 9mm ethos 100 degree

White Rabbit · #14 09-06-2008, 11:22 AM

Hi.

I'd say your next purchase should be a good barlow 2x or 3x. This will basically double the amount of eypieces you own. If you have 2x your 12mm becomes a 6mm and so on. Really handy items.

GiveItAGoGavo · #15 13-06-2008, 09:11 AM

i guess 8inch is the smart beginner-whodoesnthavetimetogettoaclub scope?

Im looking at getting mine finally if possible... I always thought I would be getting at least a 10 but being a student is hard on the budget... but I do get tempted by all that extra aperture...

psyche101 · #16 13-06-2008, 09:45 AM

Hiya Taxman

I purchased a 10" Dob from Star Optics on th Highway at Mermaid Beach on the Gold Coast. which would only be a one hour trip for you. You can have a browse as many models are on display. My 10" Dob cost me $549.00 there, sounds like that might be in your budget range?
Very happy with the Dob, clarity is amazing. I shall be back there yet for a solar filter and collmination kit - have not been game enough to attempt collmination yet....

jjjnettie (Jeanette) · #17 13-06-2008, 09:55 AM

The eyepieces you have now should do you for a while.
A barlow, as was mentioned will double your eyepiece range and give you more magnification.
So I'm going to suggest wide field eyepieces, 30mm or 40mm. They are great for viewing larger objects, eg Orion Nebula, Lagoon Nebula, Andromeda Galaxy, and are useful for when you are hunting smaller objects, find and centre them in the wide field then change eyepieces to zoom in for a closer look.
Another must have is a pair of 10x50 binoculars, and a camera tripod to mount them on.