Telescope suggestions for a beginner please. :)

[ManUtdFans (Alan)]

So what will be the "disadvantages" of Dobsonian over the scopes with tripods with mount/motor drive?

I am confused because I am brand new to telescopes.
eg. SkyWatcher SW135 Reflector Telescope with Motor Drive
$400

Dobsonian:
SkyWatcher 6" Dobsonian Telescope SW580
$379

SkyWatcher Black Diamond 8" Collapsible Dobsonian Telescope
$669

Is the main purpose of the ones has mount/motor drive with tripod for tracking, keep sync with planets/stars?

[linkpng (Alfred)]

Working through the questions in your last post: The "disadvantage" of the Dobsonian is that you need to push ('nudge') it along to follow the sky. At low magnification (wide field) this is not a problem. At high magnification, such as studying a planet at 200x it does become more difficult, but you can train yourself to do it.

The advantages of the Dobsonian are: (i) stability = the mount does not wobble, shake or vibrate. In real life this is VERY important. When you point it at an object it will stay there firmly (FIRMLY). (ii) The Dobsonian mount is cheap, so more money can be spent by the manufacturer on good quality optics. (iii) Dobsonians are very quick to set up, "nice" and very easy to use.

If you are new to telescopes (like all of us when we started!) go to a field night of a local society and see and feel for yourself.

You mention the 6" Dobsonian. Yes, a good instrument; nothing wrong with it, but you will see more objects, see them definitely brighter and a bit sharper in an 8" for little extra expense.

The collapsible 8" Dobsonian is also interesting, but I am not familiar with the sliding mechanism. Ask people for advice. Please note that in all telescopes it is important to have the relative position of the objective (lens or mirror) and the eyepiece exactly right. Adjusting this is called 'collimation'. I would be a bit worried that the "sliding out mechanism" may not be as stable and accurate as a rigid tube. However, it would be nice if the company has solved that problem. It is best to ask users for their opinion.

The SW135 you mention for $400 is a fairly heavy tube on a fairly light weight "EQ2" mounting in the text (but the photo shows a skinny EQ1 mounting). I think it will much less steady than a Dobsonian mount. Also, equatorial mounts are a bit more fiddly to set up and move. You have to loosen and then re-set clutches when moving to another object. In the dark, nothing is easy. Make sure the motor drive is included for this price or it will be an expensive extra. These cheap motor drives may also be fiddly. Try to find someone who has one. The optical tube of the SW135 (note the diameter is only 130 mm, not 135) is not known to me. Not sure if it is a straight Newtonian or a more complex short Newtonian plus a built in Barlow lens. Cheap versions of the last complex type do not have a good reputation.

Note that an 8" scope will gather 2.4x more light than a 130 mm scope (if both have a central obstruction).

At this point I would suggest you really need to go and see some astronomer near you. If that is not possible (if you live to far out in the desert) then you can't go wrong with an 8" Dob, although a 6" will also give you much pleasure. If you buy a used one, you can always later sell it for not much less than you paid for it. All the best.

[ManUtdFans (Alan)]

Thanks Alfred.
For Dobs, you mean mount? It has the base attached to the tube so is that mount.

To make it sturdy, we need a sturdy table or trolley, right? Is it hard to find?

I would prefer "traditional" scope with tripod, it looks need a bit of investment to get a good scope with sturdy tripod and mount.

[mulberry (Suz)]

Could I ask as well....

Is there a big difference between an 8" dob and a 10" dob? Apart from size and weight of course....

Cheers,

Suz

[linkpng (Alfred)]

Shaun, If you are in Sydney, there is an 8" with a few extra goodies on the IceTrade Classifieds for $300. Worth looking into.

[Crosslouglas (Shaun)]

I'm in near Brisbane.

[sn1987a (Barry)]

My first scope was a refractor. I bought it at a garage sale for $1.

[RobF (Rob)]

Originally Posted by mulberry

Could I ask as well....

Is there a big difference between an 8" dob and a 10" dob? Apart from size and weight of course....

Cheers,

Suz

Double the weight, 1/3 as big again roughly, 50% more light gathering power, tighter field of view. I think most people would recommend 10 over 8, but ONLY:

- if you can lift without worry
- fits in your car if you have to travel to a dark sky site

You might be a little surprised when you see a 10" or 12" "in the flesh"

[LightningNZ (Cam)]

Having lugged a bunch of these around over the years and not being built like StongmanMike, I appreciate a scope that's not a chore to take to dark sites and set up.

Even a 6" Dobsonian style reflector will show you an amazing amount compared to binoculars (which are must frankly for learning your way around the sky).

A darker sky will generally trump a larger telescope most of the time for how impressive objects look - especially nebulae. So if the only you can fit a scope in your car is to get a slightly smaller one don't let that concern you.

Hope this helps,
Cam

[glenc (Glen)]

Shaun
I suggest a 10" Dobsonian because it fits on the backseat of a car and it shows deep sky objects reasonably well. It will cost $600 new.

[Irish stargazer (John)]

For your budget, an 8" Dobsonian, basic laser collimator and one decent wide angle eyepiece to compliment those supplied would set you up nicely and give you years of fun.
My Dob is the cheapest scope I have, gives the best views and is the most often used. Sets up in minutes and great to take out to a dark site (nebulae,clusters) or just in the surburban backyard for the moon and planets, double stars etc.. Looks great in the living room too