Recommendations for a beginner telescope

[astr0]

Hi all,
I have just started looking at getting a telescope, and have so far decided a dobsonion mounted telescope is properly going to be the best for a first time beginner

I live on the gold coast so will be using it in light polluted.skies but will also take it away with need when I go camping out bush where there is non or very minimal light pollution


At the moment I am lookint at a $500 limit but am open minded and am willing to look at spending more

So basically I know nothing and relying on the knowledge and.experience of you guys to help guide me to the most suited telescope and accessories need to get the most fun and enjoyment

Thanks
Astr0

[Poita]

How strong/fit are you and how big is yr car? :)

A dob is great if visual is your thing.

Bigger is better, but if bigger means you end up not taking it or not setting it up often, then it isn't better any more...

There are plenty of IIS'ers on the Gold Coast. I'd recommend getting a hands on with a big dob and see if it is really what you want. Everyone here is pretty helpful, I'm sure some locals will chime in :)

[niko]

Given your budget and desire to take it camping I reckon you couldn't go past an 8" dob - easier enough to move around on your own, tube will lie on the backseat (cradle takes up a seat on its own) and the views will make you happy for years

[astr0]

Thanks niko for the advice
And peter
I am fairly strong / fit and I have a Ute so size is not a drama lol, but definitely want something that is fairly easy to setup and to dismantle amd that will give.me a fantastic view of the stars, (some ) galaxies amd other planets
So if I was to get a 8" dob any accessories or anything else I should know or look at getting ?

[niko]

A ute is perfect for an 8" - had one myself for years (both ute and 8")

it will come with a couple of eyepieces - 25mm and a 10mm or 15mm or similar.

The better the eyepiece the better the view but as these can be really expensive better to wait, learn the sky and try and check out some that others own before taking the plunge. The eyepieces you get will give you stunning views of the moon, jupiter, saturn and DSOs like Orion nebula, jewel box, eta carina etc.

So, buy a red torch and star map or other night sky guide (the 2013 Australian Astronomy for $25 is good) and maybe a membership to a local astro club

niko

[astr0]

Thanks Niko, Sounds like an awesome way for me to start,
Also is a red torch just a torch with a red lens ? ?
and with dob telescopes does collapsible and non collapsible make any difference ?
is there any difference with brands or are they all the same
(ie. skywatcher, Saxon, Ozscope or GSO )
If there is a difference which one of them is better ?

[Poita]

If you have a ute, then I'd be leaning towards a 12" or largerDob.
No real extra time to setup, and the 12" lets you see a lot more than an 8".

[astr0]

I am currently looking at getting a (gso) 10" dob which comes with a Mercury Support Systems two speed focuser upgrade and an 8x50 finder
That any good ?

[Varangian]

Yes, this is exactly what I would go for. A 10" Dob is in your price range and it is much more mobile than a 12" Dob and will allow you to see more than an 8". The focuser on the GSOs are smooth and allow micro focusing, the finder is also a right angle so you won't put your neck out! You'll get 4 plossl eyepieces (6, 9, 15 and 25mm) which will take you a long way. Clear skies.

[AstralTraveller]

I have a GSO 10" and it's nice enough. The 10" is basically the same length as the 8" (due to the shorter f-ratio) though fatter but collects >50% more light (the actual ratio is 100:64). It can't beat my 6" refractor on planets or the moon but it eats the refractor on DSOs.

The base will come as a flat pack. I recommend painting all the cut ends where you can see bare particle-board before assembly. I used two coats of watered down PVA wood glue followed by two coats of outdoor paint. After assembly I ran a bead of silastic around all the joins. The base is now really solid and will stand years of dew and perhaps even a bit of rain (though I've never been caught yet - fingers crossed). I bought my 16" second hand and this wasn't done. As a result it is starting to degrade and I'll have to make a new base in the next few years.

[simmo]

Hello astr0 and welcome.

I just recently got into astronomy and purchased a 10" dob. So far nearly every night I have been blown away by the views. It's also quite challenging hunting dso's. The planets and the orion neb will stun you first time. If you can get one second hand then go for it you won't be dissapointed. Try it out though before you buy it. My local astroshop has a try before you buy night every thursday and maybe a shop in brizzie will to.
A couple of points (if you do buy dob scope): - if you're going to sit down take an adjustable chair (i'm using an office chair at the moment) or if your standing take a milk crate or something like cause your back will love you for it. I know you will probably thinking about other gadgets but this was the first thing recommended to me in my post and now with a little time under the belt I have definitely understood why.
Free software that's cool is 'Stellarium' and for charts I'm liking 'Cartes du Ciel'. You can print off charts for the night but it takes a little toying around to get used to. It even has asteroids listed which I think is cool as well as being free to download.
Don't forget mozzie repellant if you have them around it sucks if they get bad and probably purchase some lens cleaner as your plossl eyepieces that come with most scopes new mean you have to get close at high mags. My wife took one view with her long eyelashes and that was it for the night on that eyepiece. Camera shops usually have a good range and my eyepiece has never looked better now.
The reason I put this stuff down is that I have had to use them straight away and they are things that you might factor in. Luckily so far most of it has been cheap or free.

Good luck
Simmo

[AstralTraveller]

Absolutely!! I have the Bintel adjustable chair and love it. Perhaps get by with something else for a while but as soon as the budget allows get the chair. It's amazing the difference comfort makes to viewing pleasure - and the amount of detail you will see. In a similar vein, once the weather starts to cool down take care to stay warm. Things looks so much better when you can feel your feet and your ears aren't about to drop off.

[naskies]

Since you're also thinking of astrophotography... you may want to consider something like a Skywatcher Flex-Tube where you can adjust the distance between the primary and secondary mirrors.

Solid tube Dobs often don't have enough "inward" focus travel for cameras, without the use of extenders. Taking shots of the entire Sun and/or Moon are a great way to get started with astrophotography, and it's much easier if the whole object fits into the one frame.

[ausastronomer]

Hi David,

If your 6" refractor is outdoing you're 10" dob on the moon and planets, I think something isn't quite right with the 10" dob.

I think one of the following issues may be at play:-

1) miscollimation.
2) thermal cooling and stability issues.
3) an astigmatic secondary mirror which can be easily fixed.
4) a dud primary mirror, which isn't so easily fixed.

I have two 10" dobs, one is a 10"/F5 with a very good GSO mirror (the secondary was astigmatic when I got the scope) and the other is a 10"/F5.3 SDM with a Mark Suchting mirror. There isn't a 6" refractor on the planet which will outdoor either telescope as a lunar/planetary instrument.

Cheers,
John B

[ausastronomer]

Great choice. Clearly the best way to go for someone who wants a visual telescope as opposed to an imaging instrument





I think a 10" is a better choice than an 8" if storage and transport aren't a major concern. The 10" is the same length as the 8" but a bit heavier with a larger footprint. The 10" is still easily handled by one adult. As David said the 10" collects 50% more light than the 8" and this is a very worthwhile and noticeable gain, particularly if you are observing under anything less than pristine black skies. In a 10" scope most of the bigger brighter globular clusters are bright and sparkling and resolve nicely. In an 8" scope they can be somewhat lacklustre. An 8" scope is the largest of the small telescopes, a 10" scope is the smallest of the large telescopes and the aperture at which DSO viewing starts to happen on most targets. There is a lifetime of viewing with a 10" telescope. If you went with an 8" you would want something bigger in a very short time.

$400 will get you a solid tube 8" GSO dob from Andrews and $600 will get you a solid tube 10" GSO dob from Andrews. These work well and generally have very good optics for mass produced telescopes

If you can stretch the budget I would look at the 10" Collapsible tube dob from Skywatcher.

http://www.ozscopes.com.au/dobsonian-telescope-skywatcher-black-diamond-collapsible-10-inch.html

It's $849 and if you hunt around you can probably get it for a bit less than this.

Cheers,
John B

[ausastronomer]

Here you go, one is listed in the classifieds and just had a price drop to $550 . A great deal on a 2mth old scope with quite a few handy extra accesories like the Telrad and laser collimator

Pick it up in Brisbane, it has your name all over it :)

http://www.iceinspace.com.au/forum/showthread.php?t=99860

Cheers,
John B

[Tamtarn]

I agree with John that's a great deal for $550
Barb

[brian nordstrom]

:thumbsup: + one on that .
Brian.

[brian nordstrom]

;) Hi John , I to have a 150mm f/8 Saxon with a fitted Chromocor as well as a nice 10 inch f/10 newt and on the moon and planets these two are basically identical . A lot depends on the given night .
Have you ever looked thru a good 6 inch frac ? they are the best up to a given size ( 8-12 inch Joe blogs reflector , not the multy $1000's hand made babies like you have , nice ) and thats not just the views , cool down , set up/down ease of use and lots of other factors come into it .
Brian.

[ausastronomer]

Hi Brian,

Some of the best on the planet in fact. Astrophysics EDF 155/F7, Astrophysics EDF 160/F7.5, Takahashi TOA 150/F7.3, Takahashi FS 152/F8

The Tak FS152 is a flourite doublet and not quite to the standard of the other 3 which are triplets, but it's still a very fine telescope in every sense of the word.

The views in the 6" refractors are aesthetically nicer and for want of a better term "cleaner" than the views in a 10" newtonian, but they cannot match the larger telescope for resolvable detail, when conditions are favourable, seeing is good and the newtonian properly cooled and collimated. The view in the newtonian is a little bit "rougher" than the views in the refractors, due to the effects of diffraction, but it has more detail to offer, if you are prepared to spend the time on the image. That is simple physics.

Cheers,
John B

[ausastronomer]

And I have used them much bigger than 6". Here is a photograph of the 15"/F12 D & G refractor I used for two consecutive nights at Comanche Springs in Texas in 2007. It might not look that big but the little finderscope sitting on top of the main scope is a 6"/F12 D & G refractor. There is a 5"/F12 D & G refractor mounted underneath on the blind side of the scope, which is another finder scope.

There is also a picture of me behind the wheel of this monster.

Cheers,
John B

[brian nordstrom]

;) now thats a refractor , lucky you and merry Christmas .
Brian .

[madbadgalaxyman]

People who recommend that a beginner should start with a 12 inch telescope are people who usually have little experience with comparing the useability of many different telescopes and optical designs. There are plenty of people who will tell the beginner to get a 10 inch right away, and this may be right for some beginners, but it is surprising how often the "10s" end up being infrequently used.

I have said this a few times before and I will say it again..... the best telescope, however big or small, is one that you are able to use frequently.
This means that it is best not to get a giant "white elephant" that is too big for the beginner to handle or to transport

In general, an 8 inch telescope could satisfy an adult beginner for a long time. An 8 inch Schmidt-Cassegrain or an 8 inch Dobsonian is fairly easy to move around and set up, so this is what I would probably recommend for an adult person starting in astronomy.
(However, I have known some of the smaller ladies who prefer a 6 inch Dob, or even a four inch refractor, on the grounds of its greater ease of use!)

The idea of a 10 inch telescope is very seductive to beginners because of the "large and powerful" image..... BUT the size and especially the weight of a ten inch telescope quite often presents considerable difficulties for someone who is not used to using telescopes and who wishes to cart the telescope to a better viewing site. There are quite a lot of ten inch telescopes sitting unused in people's garages simply because they are substantially bigger and heavier than 8 inch telescopes.... and therefore they are harder to use and to set up and to transport. Furthermore, it is best to learn to use a smaller telescope, before moving on to a bigger one, as smaller is easier to handle.
(Some people seem to take to the "10 inchers" right away, but a large number of beginners find them unwieldy; an 8 inch telescope will get more use by a beginner, simply because it is easier to set up! )

[[ For instance, when I was a beginner, I had a large and long and heavy and impressive looking 10 inch F6 Newtonian with an iron metal tube, that got very little use due to its size and weight.
My solution to this problem was to shorten the tube, and I ground a 10 inch F4 mirror to fit the tube.....the optical compromises of the shorter focus, and my poor optical skills(!!), made no difference to the views of most deep sky objects....and the 10 inch F4 Newt. tube assembly fits on the back seat of a small Japanese car! ]]
[[ A 10 inch Schmidt-Cassegrain is still a Big and rather heavy telescope, despite its compact optical design....for some reason, nearly all 10 inch telescopes seem to qualify as "big". Certainly, an 8 inch S-C is much more easily portable than a 10 inch S-C! ]]

In general, a 12 inch telescope, of whatever optical design and mounting design (and I have used several different designs), is a large and heavy object that is difficult to move around. In general, beginners do find it difficult to handle, and set up, and use, a 12 inch telescope, so I would strongly discourage beginners from starting with a 12 inch. ( an 8 will get a lot more use!!!)

These intuitive observations can be expressed mathematically;
if we scale up an 8 inch telescope to a 10 inch telescope and then to a 12 inch telescope, using precisely the same materials and precisely the same design for both the optical tube assembly and the mount, then:
(1) The 10 inch will be twice as heavy as the 8 inch.
(2) The 12 inch will be more than three times as heavy as the 8 inch

This is why my intuitive observations are correct!!

A 10 inch is always a large object, and 10 inch telescopes are often heavy. (It will, in most cases, be considerably harder to lug it to a dark sky site than an 8 inch telescope.)

A 12 inch is nearly always a conspicuously large and heavy object;
so, despite what you may have heard, a 12 inch telescope, in nearly every case, does considerably exceed the limit of easy portability and set up
( I have set up 12 inch Dobs, 12 inch Schmidt-Cassegrains, and I have even set up 12 inch Newtonians on heavy German Equatorial mounts ).

There are a lot of people around who do get good use out of apertures of 12 inches and above, but these tend to be experienced amateurs!
How many times have we seen a beginner start off with a big telescope, and then end up rarely using it?

cheers, madbadgalaxyman

P.S. A lot of the people who will tell you to "get a 12 inch right away" are young blokes in good physical condition.
(when their initial enthusiasm wears off, will they still feel like lugging a massive heavy object to the viewing site?)
When you are "bobbing on" and you also have a "dicky back" (like me!) , or , god forbid, if you are of the female gender, your perspective as to what is a useable telescope is very different.

[mithrandir]

... which is why when I make suggestions I always say to stick to something you are comfortable transporting and setting up.

Have you seen the video "a C14 is a small scope"? :)
Part 1 http://www.youtube.com/watch?v=TBawz69qo_A
Part 2 http://www.youtube.com/watch?v=IwVg1M6bURI

[ausastronomer]

Hi Robert,

Probably less times than you see a beginner start with a telescope smaller than 10" and rarely use it because they are unimpressed with the quality of the visual images, particularly as we are affected by ever increasing urban light pollution.

I agree that a 12" telescope is really way too much for a beginner to handle, particularly if it is a solid tube telescope. I think a 10" scope is handled reasonably easily by an adult particulalry as dobsonians are a lot shorter and lighter than they were 20 years ago. In addition the newer collapsible tube versions make things easier and lighter again. Twenty years ago a 10" telescope was a big telescope, by todays standards it's a small telescope for visual use. When Andrew Murrell got his 20"/F5 in the early 1990's it was the largest amateur telescope in the Southern Hemisphere. By todays' standards it's a baby.

Cheers,
John B

[Larryp]

I used to have big refractors years ago, and found the bigger the scope, the less I used it. Big scopes are good if you have an observatory, but if you have to carry them, set them up and take them down again, they are a pain!

[madbadgalaxyman]

John,

I think the 8 inch vs 10 inch controversy , as to what would be the best aperture for the beginner to start with, boils down to what kind of person is going to use the telescope. You say start with a 10 and I say start with an 8.......
Oh well, experienced observers have always differed about such things.

For instance, some of the ladies do find even the average 10 inch Dobsonian to be too large to handle. I have even known some beginners who find any Newtonian to be too fiddly! Also, many (but not all) people do find that the views in an 8 inch, while not exactly bright enough to burn out your eyeballs, are interesting enough to sustain their interest in astronomy.

Furthermore, some people seem to find setting up and collimating a telescope to be a real pain, and others don't!
Also, as humans are subjective creatures, the very same view of an astronomical object (in the same telescope) can be either deeply impressive or deeply unimpressive, depending upon the person doing the looking.(as we know from public star parties)

You would probably recommend a 10 inch telescope for a beginner; I do agree with you that the views of deep sky objects are Very Noticeably more impressive in a 10 inch than in an 8 inch, as the 10 inch has about 56 percent more Light Gathering Power than the 8 inch. The jump in LGP is much larger between an 8 inch and a 10 inch than it is between a 10 inch and a 12 inch. Indeed, neglecting light transmission and contrast and suchlike, a 12 inch has only 44 percent more light gathering power than a 10 inch (while being about 70 percent heavier than a 10 inch)

My personal view is that an 8 inch Dobsonian is significantly easier to set up and transport than a 10 inch Dobsonian, and I give the "easier setup & transport" factor a greater weighting than the brighter views attainable in a 10 inch.
My opinion is that an 8 inch is more likely to be used frequently by a beginner than a 10 inch, so that is why I recommend an 8 inch for a beginner instead of a 10 inch......but the needs of the beginner and "type of person" he/she is could sway the decision in favour of a ten inch telescope.

cheers, Robert

[M110]

Celestron 6se. I started with Skywatcher 8" dob and hated it. I called it it the point and hope scope, I am not the most patient person. Sold it and and bought a 6 SE. Better views through it, half the weight, go-to and track your your objects, not having to constantly nudging your scope. You take pics with it, not faint DSOs, but bright ones like the Pleiades, etc., and lunar and planetary imaging. Bought mine Andrew's Communications $1600 posted down to Tassie. So happy now I have got something useful, and would highly recommended it.

[vaztr]

Andrew,

I think your post sums this thread up nicely. 8", 10", 12", reflector, refractor, it really doesn't matter. It's what you'll use that keeps you in astronomy that counts.

I understand your frustration with a point and hope scope and there are certainly nights when I wish I could just 'dial in' a location to find a DSO in the middle of the FOV, but for me half the fun is the challenge of finding stuff for the first time.

Regards

Vaztr

[ausastronomer]

Hi Andrew,

If you get better views through your 6" SCT than you did through your 8" newtonian there was clearly a lot wrong with the 8" newtonian.

There are several reasons within the laws of physics as to why an 8" SCT cannot equal the visual performance of an 8" newtonian. All things being equal, a 6" SCT cannot get remotely close to the performance level of an 8" newtonian. Generally in fact, a 6" newtonian will perform to the same level as an 8" SCT.

1) Larger central Obstruction
2) More air to glass surfaces 2 sides of the corrector plate and a star diagonal.
3) Closed tubed design which hinders thermal stabilisation of the telescope.

If you prefer the ergonomics, imaging capability and GOTO capability of the 6" SCT I can totally understand that, but better visual views ? Something seriously not right with that 8" newt !!

Cheers,
John B

[madbadgalaxyman]

(I am going to keep this thread at the level of "recommendations for beginners", so I won't go into extensive optical details)

Today's 8 inch Schmidt-Cassegrains do underperform a good 8 inch Newtonian, but the difference is not - in my view - as great as you say it is. The older Schmidt-Cassegrains developed a really bad reputation amongst observers due to: light losses due to the large number of surfaces in the optical train, and poor optical accuracy, plus the inherent limitations of the large central obstruction causing a lot of light to end up in the diffraction rings around the airy disk (around the "star image", if expressed in popular language).

The "defocusing" effect of the diffraction from the large central obstruction means that the optics of an S-C have to MORE accurate than the normal optical tolerances necessary for sharp planetary views, yet the optics of the old Meade and Celestron Schmidt-Cassegrains were, if anything, pretty bad.

However, some of the new S-Cs do have decent optics, and the light losses in modern Schmidt-Cassegrains are not any worse than in a Newtonian, due to high reflectivity coatings on the mirrors and due to the availability of coated corrector plates and high-reflectivity star diagonals.

I own a well-coated modern Celestron C8 (8 inch Schmidt-Cassegrain) which I use together with a 99 percent reflectivity diagonal; the light gathering power of this telescope is NOT reduced relative to a Newtonian of the same aperture, because of the modern coatings used throughout the light train. This C8 is about as good on Deep Sky objects as an 8 inch Newt., though the planetary detail visible in the C8 still suffers due to the limitations of the Schmidt-Cassegrain optical design.

cheers, Robert

I think that the 8 inch S-Cs are certainly one option that should be considered by beginners, as they are reasonably quick and easy to set up. Most that I have looked through do seem to suffer compared to a Newt., when it comes to planetary views, but at least you don't have to lug a large and heavy object to your observing place!

Has anyone ever lined up a number of very recently manufactured 8 inch-Schmidt Cassegrains and assessed their planetary performance? As I mentioned, the optics of this design have to be accurately made in order to achieve decent performance on the planets, yet commercial telescope optics are traditionally noted for their variability in quality rather than for their consistently high standards!

[M110]

I am not patient enough for a dob. So much observing time was wasted, just trying to find something to look at.

[M110]

3 other people, who all spent time with both scopes, agreed with me. The SE outperformed the dob

[madbadgalaxyman]

Dear M110,

If you are comparing a 6 inch Schmidt-Cassegrain with an 8 inch Newtonian, and the 6 inch produces better views, I completely agree with John that there must be something severely wrong with the optics of the 8 inch Newtonian.....

Several possibilities suggest themselves as reasons for the severe underperformance of the 8 inch Newt:

- very poor optics of one or more components of the optical train
and/or
- very poor eyepieces
and/or
- severe miscollimation of the optics
and/or
- severe mechanical strain on one or more of the optical elements.

cheers,
Robert Lang

[ausastronomer]

Hi Andrew,

I am not disputing what you saw. I am trying to get you to understand that if that's what you saw, there was something horribly wrong with the 8" dob, including all the optical issues Robert mentioned, asuming that both telescopes were properly cooled.

Cheers,
John B

[Varangian]

Well if you don't have the patience to hunt the sky clearly you need a goto Dob:thumbsup:

[brian nordstrom]

:shrug: Ouch Andrew , thats the whole idea of amaterur astronomy ,, learning whats out there and the feeling of actually finding a galaxy 20million light years away is way better than just looking at it ?? what do ya say ?? , if you want to just look , google it , its all here ( Hubble photos ) , but the hunt is where its at mate .sorry to say .
Brian.