12" dob

[Scorpius51 (John)]

Originally Posted by madbadgalaxyman

As I keep on saying in these beginners forums: "the best telescope is one that you are able to use frequently and easily, without great struggle and stress"

That is why I recommend an 8 inch Dobsonian for beginners!!

Spot on, Robert!

[madbadgalaxyman (Robert)]

Originally Posted by Scorpius51

Spot on, Robert!

When I was "growing up"(astronomically!) in the 1970s, way back when dinosaurs roamed the Earth, the biggest instrument we could usually afford was a 6 inch telescope. So we learnt to handle telescopes properly using smallish instruments and we learnt to observe using modest Light Gathering Power.

It takes time and effort to learn how to use telescopes and to learn how to use your eyes to observe. It is easier to do this with a 6 inch or an 8 inch than with a 10-12 inch.

We didn't have large apertures available cheaply, in those days. There was no temptation "to go too big", as anything over 6 inches was expensive.

I, personally, favour an 8 inch Dob for beginners, though I am aware that some of my fellow experienced amateurs would say "go for a 10 inch Dob". However, I know of some people (for instance some people of the female gender), for whom a 10 inch Dob is too big to handle easily.

[barx1963 (Malcolm)]

The question of the best beginners scope is a vexed one. Every individual has different wants, abilities, pecuniary resources etc so there is probably no one right answer.
I have only been seriously observing for about 5 years and in that time my scopes have been,
130mm Newt on EQ2 Mount
8" dob (loaner from the ASV)
Meade ETX 80 Go To refractor
12" GSO dob
15 x 70 Orion binos
20" Obsession style dob
Given this progression I can state that all other factors being equal ( and I will get to what I mean by that in a moment) the 8" dob is the "best" beginners scope.
I am a typical male in my mid forties (or I was when I had the 8") and I would hazard a guess that I am pretty much the typical demographic for beginners today. Also we usually live in suburban or light polluted areas and we are time poor.
An 8" is a little bulky and heavy, but not so much that is a chore to set up. It is tolerant of average collimation (I never touched it on mine after I got it). It is big enough to be usuable with moderate light pollution. It can be transported easily to star parties and dark sky sites. It is not so bulky that the beginners better half is unlikely to complain about the monstrosity in the living room.
It is easy to use, point it at what you want to see and there it is.
No electronics to go haywire.
I agree with Robert that small aperture can help hone observing skills, but with light pollution, the lower boundary of small has moved since the 70s. My older brother was an ASV member who used the 25" Cassegrain the ASV had in Burwood back in the 70s. Back then, Burwood was still outer suburban and still had reasonably dark skies. I would hate to try observing there thses days!!
The worst beginners scope is a small newt on a wobbletronic EQ mount or a small go to ( I have had both and know all about them) When I look at the online telescope retailer around these day and see these things in the beginners section I get so irritated. It only serves to drive people away from our wonderful hobby.

Malcolm

[Scorpius51 (John)]

Originally Posted by madbadgalaxyman

It takes time and effort to learn how to use telescopes and to learn how to use your eyes to observe. It is easier to do this with a 6 inch or an 8 inch than with a 10-12 inch.

We didn't have large apertures available cheaply, in those days. There was no temptation "to go too big", as anything over 6 inches was expensive.

I, personally, favour an 8 inch Dob for beginners, though I am aware that some of my fellow experienced amateurs would say "go for a 10 inch Dob".

Again, very true!

Originally Posted by barx1963

The worst beginners scope is a small newt on a wobbletronic EQ mount or a small go to ( I have had both and know all about them) When I look at the online telescope retailer around these day and see these things in the beginners section I get so irritated. It only serves to drive people away from our wonderful hobby.

Malcolm

Ditto! A real frustration, but people get taken by purchase-fever.

I currently favour my 10" Dob over my 8", but only because the 8" is mounted on an HEQ5 Pro. The Dob is so much easier to set up AND USE, than the EQ-mounted 8" - both take two trips to set up.

However, if I did have an 8" Dob, then it would get used more than the 10", because I could lift the whole 8" Dob with mount in one trip. It would get used even more than my grab-and-go 70mm refractor - in this case aperture rules, OK!

I would LOVE to have a 12" Dob (16", even better ), but I know that it would not get used as much as a 10", or 8". If I had to carry a hot water tank-sized Dob and mount out every session, then I would not be out as often as I am.

There is too much choice now, and it's very easy to fall victim to aperture fever, for a marginal benefit under normal city-based observing. There is a balance to be made between how often you want to observe, what you want to observe, and how convenient it is to observe. However, if you have a permanent setup, the 'rules' can change quite a bit!

The big driver here is motivation. If your passion for observing is greater than your concern for convenience, then go for it!

[madbadgalaxyman (Robert)]

In the previous threads regarding "Beginners Telescopes" that I mentioned (in this forum), most people seemed to agree with Malcolm and John and Steffen and me, that an 8 inch Dobsonian is big enough to show decent views of the planets and deep sky objects, but not so big and heavy that the beginner is put off from regular observing or taking it to a dark sky site.

There were a few experienced amateur astronomers who thought a 10 inch Dobsonian was a good start for a beginner, because the deep sky performance of a 10 inch is a significant jump over an 8 inch, but you would have to be the sort of person who doesn't mind moving around a rather large and heavy and unwieldy object.

In any discussion of "beginner's telescopes" you also get one or two 'refractor fanatics' who insist that the optical quality of their small refractor is such that a four inch refractor is a good way for the beginner to start; but a telescope of under 5-6 inches of aperture is so very limited for deep sky viewing that you always end up looking at the same handful of objects if the sky is light polluted!

[barx1963 (Malcolm)]

Originally Posted by Scorpius51

The big driver here is motivation. If your passion for observing is greater than your concern for convenience, then go for it!

That is the big point. An ideal beginners scope is one that shows enough that the beginner gets "hooked" but not so big/heavy/bulky/fiddly to setup that it is easier to stay indoors and watch My Kitchen Rules that get out with the scope.
When I had my 130mm as my only scope, the sheer hassle of polar aligning and then trying to navigate to find anything meant it sat unsued on many clear nights.
Once I had the 8" the clear nights without use were almost zero.

Malcolm

[Varangian (John)]

Originally Posted by Steffen

That's an interesting data point. The 8" GSO Dob (that a lot of people will be familiar with) weighs about 10kg for the rocker box and 10kg for the tube. So, both parts of the 12" Dob will weigh as much as the entire 8" Dob.

Also, keep in mind, what you can and cannot carry doesn't just depend on its weight. I could carry a 20kg tube easily, but a 20kg rocker box not so much, because of its awkward shape.

Cheers
Steffen.

Yes indeed. The 12" rocker box is very cumbersome, there's not much way around it if you have to lift it. I drilled some holes into the OTA up near the primary mirror end to assist with transportation of the tube. I removed the primary first to ensure no metal shards (or anything else accidental) landed on the primary. It's attached with bolts with lockable washers so it's not going to pry loose. The handle assists with moving the OTA from the shed to my car a great deal. The mount, well that's still cumbersome.