General purchase advice for first scope

TimboS (Tim) · #1 17-02-2009, 02:27 PM

Hi All,

I've decided on a new telescope for the Mrs to replace the good ol' 10x binoculars, and new to the forums so hoping not to sound a bit stupid

I've been researching the good, bad and ugly for a while now, (predominantly on this forum

), and it would seem as though the advice of what to buy for a beginner is relatively straight forward.

Just to make sure I am not making a mistake before forking out the hard earned cash, I thought I would run my thought processes by you good people.

So, here we go:

Dollar wise - up to a grand.

Type wise - Dobsonian for sure, but space is at a premium in my house (no pun intended!) so I think a reflector or Maksutov would be best.

Brand - Skywatcher seems to have some good stuff.

Use - general point and stare, plus learn to use star charts, plus astrophotography with my Canon EOS450D a little later on.

Mount - At the very least an EQ3-2

Put it all together and the answer seems to be:

Skywatcher SW500 or SW600.

I also think dual drives and hand controller would come in handy for now, and for the future. It's only $100 more so why not.

Given that space is a premium, what about something like the Skywatcher MAK127? Right on the end of the budget though...

In terms of other "goodies" to go with the scope, I had thought about maybe a 2x Barlow or higher power eyepiece to get greater magnification than the supplied pieces. Probably a Barlow from the better eye relief, but would there be anything else I should really have from the start, and I mean *really* have since a grand is at the very limit indeed.

Hopefully I'm on the right path.

Tim

Jay-qu · #2 17-02-2009, 02:41 PM

Hi Tim,

I recently got my first serious scope. The way it was conveyed to me as I read the threads is that the scope is half the instrument, the other half is the eyepieces. When buying a scope it is unlikely that you will get decent eyepieces, so I spent about half on each (actually a little more on the EP's).

My methodology was buy as much aperture as I could afford (ended up with 8") - which obviously means its going to be a dob. It was a Syta (identical to the skywatchers).

You would be surprised how little room these guys take up, when stored pointing directly up it takes up less room than my old 60mm refractor!

I am really happy with this purchase and look forward for the smoke to clear down here in vic so I can get some better views.

Hope this helps,

Jay

TimboS (Tim) · #3 17-02-2009, 02:48 PM

G'Day Jay,

Thanks for that info. You have good timing - I was just reading a review on the MAK127 and it said more or less the same thing about the eyepieces!

I can't help but wonder, if you buy a scope that says it can do 300x or 400x or whatever, and that sounds pretty high to me, how many people actually use that on a night by night basis or simply use really high quality but lower power eyepieces ?! I mean, how much magnification is needed to see Jupiter and Saturn with the naked eye (assuming a 6 to 8" aperture mind you).

Tim

Jay-qu · #4 17-02-2009, 03:05 PM

Well the general rule of thumb as you have heard is double the aperture in mm - so 400x for the 8". But in light polluted skies on a day to day basis I dont think its worth going past 200x. When the seeing is good then you might push it towards the scopes limit.The highest magnification I purchased was 170x, I will go bigger one day (either via a barlow or shorter focal length or both

) but right now I dont think I need it.
As for the exact power touse.. Im not sure if this is correct so someone feel free to jump in.Jupiter's angular size is typically between 30 and 45 arcseconds, so even at 100x it will appear to be at least 3000 arcseconds or .8 degrees... hmm that seems a little big.. as I said Im not sure if thats right

rmcpb (Rob) · #5 17-02-2009, 03:17 PM

Your thought processes are great but I would not agree about the space issue. My 8" dob takes up less than an 18" square when standing straight up and can easily be tucked away in the corner.

As for the eyepiece issue I will give my standard answer. Use what comes with the scope for a while, the eyepieces that come with most scopes these days are actually useable so don't be in too much of a hurry to throw them away.

A good barlow would be a better purchase in the beginning and here I am meaning Televue or Orion Shorty Plus type.

If you get a newtonian then a collimating eyepeice is essential.

If you get a dob then a Telrad is a fantastic option and an observing chair (can just be any old chair).

Then you will need charts and a red torch.

Hope this is not too much rambling.

TimboS (Tim) · #6 18-02-2009, 12:45 PM

Space is indeed one of the key issues, but it seems an upright Dobsonian can alleviate that concern. Let's consider Dobsonians for a moment then.

My price point will cover a 10" truss/collapsible model, and maybe even a 12" solid tube type (although I'll need to look into that a bit more). For backyard viewing, in the outer city suburbs, which is better? Truss or solid tube?

Are there any ongoing maintenance issues with a Dobsonian? e.g. polishing mirrors periodically?

If I want to use it for astrophotography, what sort of changes do I need to make as compared to the standard base of the unit, and what might I expect to pay? My reasoning is that at least with a Newtonian and equatorial mount I have some astrophotography capability right out of the box but it would seem that with a Dobsonian I have none.

I also wonder what shipping going to be like from Sydney to Adelaide...

There's a seperate issue as well I'd like to ask about. A colleague of mine says that if you want to see lots of things, I'll need a Go-To otherwise it will be just too difficult to go out and use a scope in "point and shoot" mode and expect to see much. Does this make sense? Is it unreasonable to expect to just take the unit out the back, look around the sky and be blown away but what is really out there? At some point you have to draw the line and say I can't spend more than X dollars.

Thanks to all.

Vartigy (Aaron) · #7 18-02-2009, 01:54 PM

Hi Tim.

I'm new myself. Had a 8" Truss SW Dob, factory EPs, for a couple weeks now.
And I must say. I'm stoked with it!

Mind you, I live in a lot darker skys than most of the posters on these forums. But I do get some light pollution in town. Especially being near the minesite.
Like the good books says "Thou must haveth more aperture!"
Aperture is king.
I can view the M42 "Orion Nebula" from my driveway with this puppy.
I've also been cruising the southern clusters around the Crux.

The best thing about the Dob IS the point and shoot method. Use your finderscope to point you in the general vicinity. The finderscope that comes with the SW Dobs are fantastic in their own right! I took mine off the other night just to casually cruise the heavens with that alone!

And your mate that told you that you need a Go-To. Ignore him. All you need is a couple images downloaded from the web, or the starchart in the latest Australian Sky and Telescope magazine, use these as a naming reference, hold up to the sky, and away you go! Surprisingly easy!

I even gave my unmodded scope a brief foray into astrophotography. Basic digital camera, held up to my EPs gave me some decent photos of the moon the other night. And a couple blurry images of DSO's.

The downside for a Dob mount is that it's not suited to astrophotography. Eq motored mounts are the way to go as you can track objects real-time. That way ensuring you dont get a blurr/trailed image on long exposures.

There are plenty of guys on here that will tell you to go straight to a Dob. Learn the skys, then down the track, get an 80mm Refractor or something similar and move into astro photography.

But each to their own. Thats the beauty of this hobby. The sky is literally the limits!

Paddy (Patrick) · #8 18-02-2009, 04:03 PM

Quote:

Originally Posted by TimboS

Space is indeed one of the key issues, but it seems an upright Dobsonian can alleviate that concern. Let's consider Dobsonians for a moment then.

My price point will cover a 10" truss/collapsible model, and maybe even a 12" solid tube type (although I'll need to look into that a bit more). For backyard viewing, in the outer city suburbs, which is better? Truss or solid tube?

Are there any ongoing maintenance issues with a Dobsonian? e.g. polishing mirrors periodically?

If I want to use it for astrophotography, what sort of changes do I need to make as compared to the standard base of the unit, and what might I expect to pay? My reasoning is that at least with a Newtonian and equatorial mount I have some astrophotography capability right out of the box but it would seem that with a Dobsonian I have none.

I also wonder what shipping going to be like from Sydney to Adelaide...

There's a seperate issue as well I'd like to ask about. A colleague of mine says that if you want to see lots of things, I'll need a Go-To otherwise it will be just too difficult to go out and use a scope in "point and shoot" mode and expect to see much. Does this make sense? Is it unreasonable to expect to just take the unit out the back, look around the sky and be blown away but what is really out there? At some point you have to draw the line and say I can't spend more than X dollars.

Thanks to all.

I reckon I would go for a dob mounted reflector. There is not much to worry about in terms of maintenance, except for collimation. If you can wheel your scope out on a trolley, then a 12" is fine, but otherwise they a fairly heavy for regular transporting. People don't seem to have too much of a problem with a 10" through which you'll still see lots if you want to go to the bigger end of things. I would also agree with Rob that a Telrad is a great investment - it can be a bit hard to know exactly where you're pointing your scope with a only standard finderscope. Ditto also to his advice re eyepieces - use the ones that come with the scope - they'll be fine and you will have time to think about what suits you if you wnat ot upgrade. As a committed star hopper, one of the best ways I found to start the whole process of finding things was to browse the sky with a pair of binoculars and then point the scope at anything that looks different. Amazing what you find! Most scopes also come with software that will help you find things by printing star charts etc. It's worth a visit to a star party to learnm a few constellations and you will be surprised once you get started how you can learn your way around the sky. Books like "Atlas of the Southern Night Sky" are also very useful. Go to scopes will help you find stuff sooner, but I vividly recall going to a small star party seeking to learn a few more of the fainter constellations and finding that some of the experience astronomers there couldn't help as they'd always relied on go to scopes. I also know people who have limited observing opportunities and find go to scopes and Argo Navis devices help them to see a lot in their limited time.

So there are my personal biases all rolled into one! Hope its of some use.

Paddy (Patrick) · #9 18-02-2009, 04:14 PM

One more thing!

It's probably a good idea to go to a star party and have a look through a few scopes and get an idea of what things look like through a telescope. You may already know this, but even a large telescope is not going to collect enough light to provide the kind of image that you see in astrophotography. Bear in mind that whilst you'll see colours on Jupiter and Mars and Saturn's rings etc, your views of deep sky objects will be spectacular in monochrome as you will be using your night vision. (star will show colour, but not nebulae or galaxies)

Sorry if I'm telling you something that you're already aware of, but it often seems to me that people buy telescopes without a clear idea of what they may see and express some disappointment at the monochrome universe they encounter.

I'm sure there will be something happening with the astro society of SA or even some local IISers might be willing to show you some things through their scopes.

TimboS (Tim) · #10 19-02-2009, 11:38 AM

Thanks for the advice Paddy.

I spoke with a local dealer yesterday who wants to sell me a MAK102 for a little bit more than Andrews can, and size wise I'm happy to do that.

But, I've popped back on to the skywatcher website and used the compare function and yes, bang for your buck is certainly where the Dobsonians hold their own.

A couple of weekends ago I did go to a local astronomy club meet and had a look through a Bintel 10" Dobsonian and a 5" (I think) Meade Maksutov with all the bells and whistles. The Dob was better IMHO, and far cheaper, but the difference in handling was quite obvious.... I also note what you say about looking at deep sky stuff in monochrome. All advice gratefully accepted.

About the point and shoot use of a Dobsonian and where you say pick up some star charts to learn your way around, I did get the latest Australian Sky and Telescope yesterday and noticed that the star charts go out to a magnitude of +4, but an 8" Dob can (under ideal conditions I'm sure) image +14.2 (by spec). That would seem to be a BIG difference, and I know that it would be all but impossible to print on A4 paper a star chart showing all objects out to +14.2, but how does one find all the "further" stuff with a Dobsonian when pointing accuracy would seem to be so very critical?

Am I getting ahead of myself here?

rmcpb (Rob) · #11 19-02-2009, 12:08 PM

Tim,

In the beginning you will be looking at the big well known stuff that is easy to find and the Messier list objects which are pretty easy to find. As you get more experienced you tend to get better charts and atlases and pick up some software that can print out detailed charts for star hopping to the more challenging objects. Its a case of crawling before pole vaulting.

Now, of course this works and keeps you entertained if you like the thrill of the hunt BUT if you are more into ticking off lists then a GoTo system will let you "see" more per session than star hopping ever will.

TimboS (Tim) · #12 19-02-2009, 12:22 PM

He he, I thought I was getting ahead of myself

At this time I think I need to decide between an 8" collapsible Dobsonian or a SW500.

I know the former gives better bang for your buck, but I am willing to trade some of that off to buy a setup that can also give a very basic track capability for astrophotography (at least for planets). That way I can see if that also appeals. A win-win situation.

Andrews has the SW500 with dual axes drives and hand controller for $499 freight free, I presume this is a very good deal. Am I right?

Also, do I really need a collimating eyepiece right away?

I think the setup comes with 10 and 25mm 1.25" eyepieces. Given the scope specs, would a Barlow be good straight away?

Tim

Coen · #13 19-02-2009, 12:45 PM

There are a number of star charts available, free or otherwise. Getting a copy or two and making up some field of view templates for your finder and for your, say widest field of view, eyepiece are then further aids.

I personally use JR's Tri-Atlas 2nd edition (third is in preparation) which comes in 3 different scales, A, B, & C (over 500 charts). There is actually a fourth size which is a hybrid labelled M for A4 version and Z for US format paper.

I printed the 216 M charts onto A3 paper instead of the A4 and then drew some circles on some clear plastic representing 30', 1 degree, 2 degree... out to 5 degree wide circles (get the scale from the declination axis). I put the 216 charts (double sided print) together put some holes down the side and used cable ties to bind them with some cover for the back and front. A card table next to the telescope with a red light and voila laying the clear plastic with circles over the chart gives me a quick idea of what I can expect to see in the finder and the eyepiece. The M charts have stars to 12th mag and many deep sky objects, too many for some charts (being addressed in the 3rd edition, reducing clutter in the Carina region for example), there are also many double stars and variables marked.

Another atlas that I have found useful with many objects and stars down to 8.5 is Taki's Deep Sky Atlas - can't remember exactly how many charts but around the 100 mark.

Links to these atlases available in the sticky posts section.

Still it does take some time to learn to star hop as it can be easy initially to think you have a certain pattern over here but it is actually over there you are looking as it were. It does not take long to become reasonably proficient though but there will be back and forth between chart and eyepieces. A GOTO alleviates this, once aligned, and is excellent if viewing time is limited and you have more in mind that you want to achieve beyond a cruise around regions.

When starting out a pair of binos next to the scope is good, scan a section of sky, hey that looks interesting and then point the scope - great discoveries that way and they often provide a sense of personal discovery.

Ford Prefect (James) · #14 19-02-2009, 01:18 PM

http://www.uv.es/jrtorres/triatlas.html

JethroB76 (Jeff) · #15 19-02-2009, 01:23 PM

If you've got a laptop or PDA, a dob can quite easily be fitted with manual setting circles/angle finder to make a very effective and reliable push-to solution for finding objects, for say <$100
Later, if your budget permits, you could fit an Argo Navis.

Vartigy (Aaron) · #16 19-02-2009, 01:37 PM

Regarding Collimating Eyepiece.

For reflector Dobs.
I just picked up an old photo film canister, cut the bottom out of it. Pricked a small hole in the grey lid, widened it out to about 1mm diameter and used that as a "collimating eyepiece". Fits snugly in the Focuser.
Worked a treat.

rmcpb (Rob) · #17 19-02-2009, 02:52 PM

What are the specs on the SW500? Had a quick look on the Andrews website and couldn't see it.

Have a look at Mike's article on astrophotography with a dob. Its how he started in that dark art.

Be careful of giving away aperture if you can help it.....

Coen · #18 19-02-2009, 03:03 PM

SW500 is the 6 inch (150mmx1000mm) on EQ3-2, just is not labelled as such on Andrew's site.

I like the look of the SW600 (8 inch on EQ5).

rmcpb (Rob) · #19 19-02-2009, 04:25 PM

Be aware that eyepieces on equatorially mounted scopes can get into very interesting positions. This doesn't matter if the scope is attached to a camera but getting your eye to the eyepiece can be a challenge.

I would also say that those EQ mounts would only just do the job as far as basic astrophotography is concerned but would be good for general observing and some quick snaps.

If you go this way, get the 8" you won't regret it except it will take up quite a bit of room unless you fold up the mount each time you use it.