It Comes Down to Go-To vs Dobsonian + Argo Navis?

[GH1967]

Astronomy, or more to the point, the gear to look at stars, is too complicated! :lol:

This forum, and other astronomical boards, are doing my head in. So many new words and acronyms....took me two days just to figure out what 'EP' meant :)

I know zilch about astronomy other than I look in one end of a scope and see stars out the other end. I'm not even scientifically minded, more of a humanities-type person, but I really love star gazing and want to seriously get into it. I find planetariums complicated and the idea of constantly gazing and looking at charts a bit of a turn-off.

As I understand it, it comes down to this with a budget of about $4,000:

I can get something like an 8 inch Meade LX90 or one of the orange Celestrons GO-TO's that solve my navigation issues well within my budget. But they are a tad messier to set up and you simply cannot see as much through them as a dobsonian.

On the other hand, I can get a large-ish Meade Lightbridge, easy to set-up despite its size and really see some serious stuff (aperture, aperture, aperture!), BUT other than the Argo Narvis which looks/sounds complex for a newbie like me (228 pages of instructions anyone!?) Dobsonians are limited in that they have no GO-TO type features such as tracking and tours etc.

So is there a simple scope that balances some DSO visualising with a handy navigation instrument, or have I pretty-well summed it up?

Any feedback is appreciated, thanks.

P.S is the future GO-TO large aperture Dobsonians that will be sold completely as one unit instead of having to modify/add-on with after-market devices? If so any idea when will we see these on the market?

[floyd_2]

You could take a look at the Orion XX14i for a scope that fits within your budget and includes an integrated object locator. Here's one link (http://www.telescope.com/control/telescopes/dobsonian-telescopes/orion-skyquest-xx14i-computerized-intelliscope-truss-tube-dobsonian-telescope)that has a few photos and good information.

Dean

[AstroJunk]

The cheaper alternative is to join your local astro club and go out with them as often as you can so that you can get a good feel for what you enjoy viewing most and what level of technology you feel most comfortable with.

$4000 gets you an awfull lot of scope, but it can just as easilly get you an awfull lot of the WRONG scope!

The stars will wait for you, take your time and learn from the locals.

[ausastronomer]

Hi,

I agree with Jonathan 100% on this. $4,000 buys you a lot of scope but can also buy you a lot of the wrong scope.

I suggest you get to a club meet and have a practical hands on with some of the scopes there to see what suits "YOU". I wouldn't have a SCT if they were giving them away, but that's my personal preference. Tens of thousands of people worldwide, have them and love them. For mine they have issues that don't fit with my observing preferences. To others those issues I have, are non issues.

Heaps of Astro Societies around Sydney you can contact.

In addition, we have a monthly new moon Ice in Space observing get together on the lower Central Coast, at Mangrove Mountain. You would be more than welcome to come along. We will bring the telescopes, you bring the cigars, port, coffee, tim tams and party pies :)

I am guessing the next one will be on Sat 12th June. There will be all types of scopes set up there for you to use and look at. 8", 10" and 12" SCT's and some dobs from 10" to 20" with Argo Navis and Servocat GOTO. It would be wise to have a trial run before you buy, considering your budget.

Cheers,
John B

[acropolite]

I agree with the others, meet up with some locals and try before yo buy.

FWIW I have an 8 inch LX90 and they are a wonderful tool; that said, my initial choice was a dob, but ministerial veto prevented getting the dob for asthetic reasons (you can't have that big ugly thing in the house). If I were doing the same again and had a budget of $4000 I'd be looking at one of the 16 inch dobs and equipping with an Argo Navis.

[sheeny]

All good advice here, I have to agree.

But just to address a couple of points in your post...

If you are interested in looking at the stars, planets and DSOs rather than astrophotography, then the largest Dob you can afford with an Argo Navis is the way to go. Don't be fooled by the manual... the Argo is very simple and easy to use. But before you jump in, my advice is:



Get a planisphere so you can work out the bright stars in the sky. Should cost you less than $50. This will come in handy when you align your scope with the Argo;).
Get along to an astro club or star parties and look through other people's scopes to see what shakes your tree:thumbsup: (Don't just take our word for it:D)
Think seriously about a set of 7x50 or 10x50 binoculars, because they'll give you wide field views you can't get in a scope and don't cost a heap... and you'll always use them.:)

Al.

[GeoffW1]

Hi,

A most interesting thought. We already have small Dobs like that but...

From a marketing standpoint the large Dob gives you the most aperture for the money, and a good simple robust go-to would enhance such a Dob no end.

I think there is ample scope (oh no :D I can't believe I said that) for much further engineering refinement in the design of Dobs, and I have in mind some scheme which would reduce the need for constant collimation, as well as giving quick 2 star alignment.

I am trying out an ED refractor on a go-to GEM mount at the moment, but can see such a Dob in my immediate future still.

Cheers

[casstony]

It Comes Down to Go-To vs Dobsonian + Argo Navis?

Both types of computerised pointing systems work well. It's more important to find out what type of telescope suits you best; once you've done that you'll be happy with a goto computer or a push-to computer, whatever is appropriate for the scope.

Welcome to IIS :)

[norm]

Hi GH1957,

I agree with what others have said and with John's comments. $4000 can buy a lot of scope!

Highly recommend you come up to the Pony Club next month and check out whats on offer.

I'm more than happy to give you a run thru' of the Argonavis - and I consider myself a novice of that and yet to use its full potential.

I didn't need to configure and install the encoders on my scope for the Argo, but the help from Wildcard innovations is 2nd to none, so don't concern yourself too much with that. Once it's installed, that should be the end of that. As far as initializing for its use each time you view, literally < 2mins and your done (2 star alignment,, etc).

As mentioned previously familarise yourself with the night sky, one method is to download Stellarium and use that as a starter - brilliant bit of free Astro s/w.

But don't rush into it - check out whats on offer, think seriously if you're going to make the effort to get the scope out, set yourself realistic ambitions and send thru' any questions.

Cheers Norm :thumbsup:

[gary]

Like others have advised, I highly recommend the value in looking through other
people's scopes at a large variety of objects before you go and buy a
telescope of your own.

The Pony Club is certainly a good venue to often see a variety of scopes and to
meet people only to happy to share the views and to pass on their advice and
experience.

We happen to design and manufacture the Argo Navis Digital Telescope Computer,
however, I can't over-emphasize how important it is to consider the optics and the
mount first ahead of any electronics.

In the end, the electronics is simply there to assist you in locating and identifying
"stuff". But it is the looking at the stuff that matters! For example, last weekend
at the South Pacific Star Party I assisted some colleagues with sky tours using
an 18" Obsession fitted with a 13mm TeleVue eyepiece and equipped with an
Argo Navis Digital Telescope Computer. Aligning the Argo Navis at the
beginning of the night took about a minute and each time we moved to a new
object probably took about a minute to dial it up on the Argo and then push the
scope to the target. The 99% of the rest of the time was then spent with
eyeballs looking at the object.

For example, when looking at M104, the Sombrero Galaxy, it was worth taking the
time to study the dark dust lane in the ring of the galaxy, taking the time to observe
the central bulge and with some further study, gradually discerning the faint halo
around the entire object.

The Argo Navis took the sting out of finding it and other objects, especially
when you have a long queue of eager people waiting in line, but it was
the looking at the object that mattered.

As other scope owners will advise, there are many additional considerations that
go into buying a scope. How will it be transported? Does it need to be lifted?
Where will it be stored? What is the quality of the mirror? Does the
mirror cool down quickly enough? What is the quality of the materials in the mount?
Is the mount smooth to operate? Does the mount suffer from vibrations?
Does the mount suffer from wind buffeting? Does the focuser provide smooth
operation? And many, many more. All best answered by looking at and using
other people's scopes and by talking to their owners.

Once you pick the right scope with the right eyepieces, then consider the
right electronics.

Good luck!

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au

P.S.


As it says in the introductory paragraphs of the Argo Navis User's Manual -
"Don't be daunted by the size of this manual". The first thirty or so pages is
just about all you need and covers everything from putting in the batteries,
to performing the initial one time set-ups, to showing you how to align the unit,
all the way through to a tutorial on how to tour galaxies in the constellation
Fornax. The rest is reference material and describes every mode of operation in
great detail for those customers who really want to know everything. And if
there is still more they want to know, we are only an email or a phone call
away.

P.P.S

Argo Navis also supports the ServoCAT and SiTech slew and track systems,
so if you really want GOTO on a Dob, rather than just PUSHTO,
this is a popular choice.

[mic_m]

There are large aperture commercial dobsonians that come with GOTO, tracking and digital setting circles as standard.

There is the Orion XTg (http://www.telescope.com/control/category/~category_id=gotodobs) GOTO dobsonian. The 12 inch model sells for $2810 at Sirius Optics (http://www.sirius-optics.com.au/).

There is also the Sky-Watcher SynScan (http://www.skywatchertelescope.net/swtinc/product.php?id=172&class1=1&class2=106) dobsonian that comes with GOTO. However, these are not presently available in Australia.

There is the Sky-Watcher Autotracking (http://www.skywatchertelescope.net/swtinc/product.php?id=158&class1=1&class2=106) dobsonain, which will track objects you locate yourself. The 12 inch version of this telescope is available at Andrews Communications (http://www.andrewscom.com.au/site-section-10.htm) for $2399.

Then there is the Orion XX12i (http://www.telescope.com/control/product/~category_id=trusstubedobs/~pcategory=dobsonians/~product_id=09793) ($1955), Orion XX14i (http://www.telescope.com/control/product/~category_id=trusstubedobs/~pcategory=dobsonians/~product_id=09791) ($2995) and the Orion XT12i (http://www.telescope.com/control/product/~category_id=intelliscopedobs/~pcategory=dobsonians/~product_id=27189) ($1639), (plus the whole XTi series) which all have digital setting circles as standard, these are all sold at Sirius Optics.

As you can see packaged GOTO, tracking and digital setting circles is the present of commercial dobsonians!

In terms of the future of commercial dobsonians, I actually think that commercial producers need to spend time working on reducing the bulk and weight of their telescopes. A major issue for many people thinking of upgrading to a larger aperture dobsonian is the sheer size and weight of these instruments. Commercial dobsonian producers need to make something like this (http://www.opticalmechanics.com/evolution_dobs/evo-30_intro/cad_zoom/18-UC.jpg) affordable to really make large aperture dobsonians truly accessible.

Also note that an SCT is not really any harder to setup than a dobsonian (actually the SCT will be lighter and a lot less bulky). Here is a video (http://www.youtube.com/watch?v=Kz_MJQF37lY) demonstration of the Celestron Nexstar 8 SE being setup and aligned. An SCT however, has other disadvantages, such as a larger central obstruction than a Newtonian telescope of the same aperture.

One other thing to note is that you will need a power supply similar to this (http://www.ozscopes.com.au/celestron-powertank-12v-power-supply.html) to drive the mount of a GOTO or tracking telescope, or a whole lot of batteries.

I also agree with the advice given so far regarding choosing a telescope; join a local Astronomy club, talk to other amateurs and look through a number of different telescopes before making up your mind about which one is right for you.

Michael.

[gary]

Hi Michael,

Thanks for the post.

It is worth pointing out that the the picture of the telescope in your link is in fact
a commercial telescope, specifically an Obsession 18" f/4.2 UC, manufactured
by Obsession Telescopes of Lake Mills Wisconsin.

See http://www.obsessiontelescopes.com/telescopes/18_UC/index.html

The UC stands for Ultra Compact.

When Dave Kriege of Obsession introduced the 18" UC at the 2007 Texas
Star Party, he foresaw that with rising gasoline prices that many Americans would
be downsizing their vehicles and thus in response Obsession produced a telescope
with premium optics and mechanics that could fit in the trunk of just about
every car found in North America.

Obsession seemed to have got it right. Chosen by US Sky & Telescopes as
one of their much coveted "Hot Products" of the year for 2008, the UC series have
proven popular not only in North America but elsewhere in the world as well.

Now and then we get to operate an Obsession 18 UC at outreach stargazing events,
courtesy of the Three RIvers Foundation (3RF). It is a pleasure to use and since
the eyepiece height at the zenith is just under 2m, only a small step ladder or
box is required to assist most school children or not-so-tall adults.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place
Mount Kuring-Gai NSW 2080
Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au

[mic_m]

Thanks Gary,

I probably should have been clearer about the context of the scope in my link, I’m sure there will be plenty of people that will appreciate your clarification.

As can be seen from the Obsession UC product page in the link above, compact commercial dobsonians are expensive; their price point is beyond the budget of most amateurs.

In the future, I would like to see a more affordable alternative to the Obsession form commercial mass producers such as GSO and Synta.

A move away from the bulky and heavy designs commercial mass producers such as GSO and Synta have pursued to this point, to an affordable, compact mass produced dobsonian telescope would be a revelation for the all those in the community seeking portable, large aperture.

Michael.

[GrahamL]

A little harsh John :lol:

On a side note , whatever you guys are considering .. prices rideing on our high aus $ over the last year or so have made purchases quite pleasant ( unbelievably so ! ) .. I believe all the Asian companies in this market run accouints payable in US $.. whats cheap today may not be tommorow the direction our $ has gone of late. :)

[marki]

Don't waste your money on agricultural telescopes, dobs are rubbish.

Mark

[astroron]

As is your statement:rolleyes:

It all depends what you want to use the Dob for?
We all at times have a barrow to push.

[Starkler]

Irony.

[marki]

If he gets a goto EQ mount of reasonable quality he will be able to mount many different types of scopes as well as having the option of AP latter on if he so chooses. It doesn't take most people long to tire of looking at everything in greyscale.

Mark

[AstroJunk]

More Irony.

Dob owners unite!

[GH1967]

Can you elaborate on what you mean in the the bolded part below?

Most advice I am getting here and with astronomers I have met seems to point me towards dobsonians.

Astrophotgraphy will probably never be on my radar.

[marki]

Most objects are too dim to see any colour unless you use a CCD camera so they appear in shades of grey.

Mark

[marki]

:rofl::rofl::rofl:You know I am right. My aren't we sensitive, seemed quite okay to bag CATS half a dozen posts ago :thumbsup: .

Mark

[GH1967]

Thanks.

This is a little disconcerting. You're basically saying observational astronomy is colourless and soon gets tedious, and only astrophotgraphy and the colours it can bring out is really worth pursuing?

If thats the case I don't think this is dobsonian-specific, because as I understand it you see less with an EQ mount than a dob (except maybe on planets), and everything is still 'greyscale' with an EQ unless you get into photography?

[marki]

Thats about the size of it I am affraid but we all have our preferences and this is simply my opinion. As you have said it is not dob specific, even the largest amature scopes will only reveal a hint of colour as they cannot collect enough photons to fire the cones on our retina. You may love visual observing but you will never see the universe in the bright colours seen in so many of the astro mags. That is why I suggest you get a goto EQ mount. You can still mount a good size newt on it as well as other types of scope (there is no one scope type that does it all) and if you are not satisfied with visual observing you have the basic tools to try your hand at taking pics without having to accept the pain of selling off gear cheap so you can move on to other things. There are many other advantages to a goto as well e.g. finding targets quickly so you can spend more time looking rather then searching as well as the mounts ability to keep a target centered in the eyepiece. The argo navis units are good for finding things on a dob and are reasonably priced but tracking systems for dobs cost big bucks and are only worth the financial pain if you have a real monster, otherwise they are not good value. I am not against visual astronomy by the way and many on this forum love to do just that. I prefer to try my hand at all aspects in this hobby and taking pics certainly adds that missing dimension for me.

Mark

[Steffen]

Your preference is of course nothing that can be argued with, but I suspect you're mostly in love with your expensive imaging gear, EQ mount and all.

My rig is a simple visual one (just an Alt-Az mounted Mak and a laptop with assorted planetarium software) and I enjoy finding things and looking at them with my own eyes. Whenever I have an urge for colourful images with a lot of detail I can guarantee that I'm getting better, more colourful and more detail-rich images with this gear than you, simply by using the right technique.

My technique is basically to visit hubblesite or similar and downloading pictures while stroking my Mak :lol: I cannot possibly ever beat what's on offer there, so why should I spends thousands of dollars trying? Unless I'm deeply infatuated with and like surrounding myself and tinkering with expensive yet inadequate equipment. Which I'm not. But that's just my preference :D

Cheers
Steffen.

[GrahamL]

Yes visual observing is without colour for the most part.

As for tedious ? .. Not sure on that one theres plenty who never feel the need to move on to photography.. The experiance of finding and catching those photons as they left there source all those millions of years back with your own eye is not to shabby Imo.

Whatever mount your scope sits on won't effect what you see
apperture( size of the scope) and conditions will .

To divert the conversation a little back to earlier suggestions , I think its important as mentioned to spend some time with others and there scopes to get an idea what appealls to YOU.

Its not unusal for some new to astronomy to tip a lot of cash into visual gear to find pretty quickly they wan't to move on photography.

Whatever you choose its all good :thumbsup:

[casstony]

Not sure why the temperature is elevated in this thread - they're all good scopes - must be a virus going around :) .

GH1967, if you find yourself stuck in analysis paralysis just grab a 10" dob without a computer and go to a club observing night - the people there will have you looking at the biggest and best objects in a flash, all for a minimal investment. You can upgrade to Argo navis or a goto schmidt cassegrain or a bigger dob at a later date.

I would not recommend a goto equatorial mount for visual observing - too complex for a beginner.

[Satchmo]

What is it with seeing colour?. Is it not enough to be seeing light that may have been travelling even hundreds of millions of years to reach your eyes :)
IMHO opinion beginners need to get their bearings by starting off with a good visual scope first and do some time appreciating DSO's live in real time. Photography is a great place to go once you have learnt the basics and got a reall feel by direct observation of where we are in the Universe.

[michaellxv]

On the weekend I finally made it out to Stockport for one of ASSA's public nights. I looked through several different size and shape scopes and learned a lot about what I like and don't like about each. As many have said already the best option it to get out and try some.

On the specifics on Goto vs Dob. For the past 18months I have been using an 80mm refractor on a goto mount. It has served me well and I have found lots of interesting stuff to look at.

On the weekend I had the opportunity to play with a 12" Lightbridge. :cool: I have never used a dob before. Using only the red-dot finder I was able move around the sky and find various objects that I am familiar with. Then after checking a chart and some pointing in the general area of the sky I was able to find some objects I had not seen before.

Goto is nice but no substitute for aperture. The 12" is still out of my price range but I know i'll be saving up for the closest I can get :D

[Starkler]

.......... look them up on the internet;)

I find visual observing to be a personal and in some way intimate experience, whilst images on a computer screen to be rather the opposite.

Many a time i have viewed objects directly and then later looked them up online to compare what I was seeing, but I have never had the urge to spend 10's of thousands of dollars attempting to match the quality of images I can access online for free :D



Yup thats what I reckon too

[astroron]

I don't get the same feeling of awe looking at an image of The Eta Carina Nebula and the Homunculus as I do looking through my 16" scope from a Dark Sky.:eyepop:
The Nebulous Dark Lanes and seeing detail give me more satisfaction than any image ever does:):)
No Image in my opinion compares with the visual splendour of Open Clusters
or Globular Clusters such as Omega Centaurus or 47Tuc in a medium to large telescope, or even small scopes of around 4"-6"
Maybe the images of galaxies is a possible exception, but when you consider you are looking at light that has traveled millions of light years to reach your Retina,then the wonder of this fact compensates for the lack of colour in your visual image:astron::astron:
P.S.
I do enjoy the images that are taken by both Amateur and Professional
Telescope and have commented favourably on them and will continue to do so, But I will always get more enjoyment observing things myself if however possible:thumbsup:

[erick]

Sometimes, I find myself wishing that there didn't need to be that cm or two of glass in the eyepiece between my eye and the object :sadeyes:

[marki]

Nah it's a pain in the bottom mostly and it is a rare night when it all works but I have got people talking now haven't I :D :thumbsup:.

Mark

[marki]

How about a 12" on a goto, best of both worlds and offers lots more flexibility for future requirements :).

Mark

[marki]

Is the goal to beat all the other astrophotographers or just produce the best images you can? I get most satisfaction from imaging through my little 80mm apo ($800) on my secondhand sphinx ($1400). Sure my CCD cost a few bob but as others have shown great results can be had using a cheap DSLR camera so you needn't spend a fortune on gear. I have other larger scopes of many types but the sphinx and 80 apo are just so convienient to setup and deliver results I can happily live with and far exceed anything I can view visually even through the larger aperture scopes I have. The only exception I can really think of is starring at Tuc 47 through the 10" LX200R with a 17mm ethos or 14mm XW. You just fall into it and I have not seen any image of it that delivers the same experience.

Mark

[AstroJunk]

Only because I own a big CAT :P

[coldspace]

Yep we all want our Big Mac and large fries at Macca's in 30 seconds.:rofl:(Instant satisfaction)

I see you are in Sydney,so unless you are prepared to travel well ou into the country all the time then visual stuff will quickly bore you in the city.

I love visual, but only when I get out to pure dark sky 3 times a year with at least 12 inch eyes but then after looking through 20,25 and 30 inch scopes in dark skies on a few occasions I have been spoilt.

Don't have the time nor patience ATM to learn the hard art of imaging,maybe later i life when buisiness/family comitments settle down.

So if you want instant colour gratification on most Messier objects and a lot of the NGC ones in polluted skies, do what I did:thumbsup:.

Get a Mallincam VSS and a goto Cat like the C8 or bigger like my Meade 12 and blow your mind and family/friends away on upto 30 objects a night in suburbia. Best piece of gear I ever bought for this hobby, and you can still use the Cat for visual use as well.

You can use the video systems with Dobs if you have some tracking like servo cat.

I would get along to a few club meets in dark skies first if you can to see what you think you will need.


Matt.

[GH1967]

I'm a bit confused by your post because on the one hand you say:



But on the other hand:



So are you saying astronomy quickly gets old in cities unless you have GOTO-tracking ability?

[coldspace]

What I mean is,

You will run out of objects to view visually if your light pollution is bad.
Most objects are so faint even a decent 12 inch mirror has trouble seeing them, its the sky glow from all the city lights that drain out this very faint light from outer space.
Don't get me wrong, you can still see things in the city like planets/openclusters/ some globs/and M42 thegreat orion neb if condtions are clear.

To really get long term enjoyment from visual astronomy you need to go to darker skies like at least 100ks or better yet 200ks out of town or more.

In suburbia, goto tracking as with the meades/celestrons or push to object finders such as Argo Navis or the new orion XX dobs is a must to find things as conventional visual star hoping with a push around dob for a bigginer will be very,very,very frustrating trying to find alot of things.
This is why you see alot of bigginers jumping in and soon the scope get put in the corner of the lounge room gathering dust.
I know, done this before twice over the last 15 yrs till I got the bug again and technology had made my instant satisfaction needs viable.

I quickly got bored with my 12inch Meade ACF in the suburbs so bought a high sensitivity colour video system that just sits in the eyepiece holder and displays in real time on a screen the object most in colour in real time that are invisible in the eyepiece of a 12 inch in moderate light pollution. The camera is thousands of times more sensitive than our eyes so can pick up things we can't see. It works well on moon/planets as well.

You can see why most venture into somesort of electronic imaginging if you have bad light pollution.

Get a large dob if you want say 10 inch or bigger, the solid tube 12 inchers are good value but are about the size of a hot water system, the orion truss 12 and 14 incher truss pole dobs with the auto locater look good but be prepared to take it out to some dark skies to be able to see a massive difference but they don't have motor tracking so down the track if you want to try video or conventional imaging down the track you can't.

I love visually using the scope as well even in suburbia with the kids on planets/moon and a very few other objects but soon got bored with it unless in pure/pristine dark skies 200ks out from Brisbane or more but mst people don't have the time to do this more than a few times a year.

See if you can get out to one of the club meets and try some gear first.
Conventional astro imaging is a very big learning curve and plenty of dollars need to be invested into it even to set up a basic system.
I went the video way for home use as its far easier to learn and gives me alot of instant satisfaction if I can only spare a few hrs a week to get under the sky.

[rat156]

Firstly, let me remind you all that a Dob is the mount, the telescope in general is a Newtonian reflector.

For someone starting out with little knowledge of the night sky and little knowledge of what they want to do in Astronomy I would recommend a smallish (8-10") SCT. I know they work pretty well for most things, but will let you down on the very faint stuff. I know this because that's the way I started a few years ago.

Now look at the list of stuff I have in my sig. and you'll see that my preference shifted to photography pretty quickly, I enjoy the satisfaction of taking the image, be it deep sky or planetary. That said I still like to go visual every now and again, I disticntly remember the first time I saw 47Tuc through an eyepiece with my 8" SCT.

For my own personal preference the SCT beats the Newt because of the relative lack of coma in widefield views and the longer native FL is good for planetary and comet observations as well as galaxies. The Newts win in cost per inch of aperture without doubt, but sometimes this is unuseable in cities because of the overwhelming LP.

Cheers
Stuart

I love Goto, as an absolute beginner can be up and going and looking at stuff in minutes. I would not advise any beginner to get a goto GEM in the Southern Hemisphere, polar alignment is too hard for a beginner and they'll quickly bore of the task. Let nature take it's course and if the beginner enjoys taking photographs through their scope then they'll graduate to a mount that's more appropriate (there goes the $4k budget). Otherwise they have a good all-round scope that's easy to setup and transport with a mount that knows where all the "cool" stuff is.

[Satchmo]

Just to clarify here, the eyepiece focal length sets the magnification for a given amount of aperture. There is essentially no significant difference between say an 8" SCT and an 8" Dob newt used at the same power for DSO observing except perhaps convenience and usability.

[ausastronomer]

In general terms that comment is correct. With "most" deep sky objects you see infinitely more, from dark skies than you do from suburbia.

However, there are plenty of people who have spent a lifetime observing the Sun, Moon, Planets, double stars and variable stars from suburban light polluted skies and never venture from their backyard. All of these types of targets are of course unaffected by light pollution. If you focus on these types of objects and go deep enough into them, there is enough to keep you going for several lifetimes without using a drop of petrol.

Me personally, I observe the moon planets and double stars occasionally from home and regularly travel to dark skies to observe DSO's.

Cheers,
John B

[casstony]

One important consideration when choosing between 8" or 10" in a light polluted backyard is that, in my experience, a 10" will gather enough light to use a UHC filter whereas an 8" will not. The improvement in the 8" is so marginal that it's not worth bothering with the filter.

[rat156]

Except that the eyepiece focal length for a shorter native focal length scope will be shorter. To put it more simply, to get 100x magnification with a 2000mm focal length scope (typical 8"SCT), you need a 20mm eyepiece, to get the same with a 1200mm focal length (typical Newt?(f6)) you need a 12mm eyepiece. Now, we all know that typically a 20mm eyepiece will usually have better eye relief and be less prone to "kidney beaning" at similar price range to the 12mm equivalent. So for high power stuff (lunar and planetary) the longer the native focal length of the scope (IMHO) the better. Of course there is the tradeoff between contrast and central obstruction, but this is the beginners forum and the views will be wonderful either way.

The 26mm Plossl that my 8" SCT shipped with was a fine eyepiece, I rarely used much else (I discovered Barlows and powermates), though I have a 13mm Nagler that I also love to use (but it suffers from the kidney bean effect). Now I don't know, but I've also heard that the widefield eyepieces are terrible on short FL Newts because of the coma towards the edge of field, is this also true?

For the beginner, with little knowledge of the night sky either scope is OK, but I feel that the SCT would be better if you can afford one. Of course there's always good ones coming up secondhand on here and fleabay if you're at all patient. Most of us succumb to "aperture fever" at some stage and will sell off the smaller scope relatively cheaply.

Cheers
Stuart

[GH1967]

Been looking around at various mounts and talking to people and decided I like the 12" Meade Lightbridge.

Its portable and has enough aperture (with filters) to allow city observation (true?). I regularly go camping so will use it in the darker bush areas.

I was going to buy an Ipad and I notice they have the Skyvoyager program which will assist me with learning night-sky navigation. Another reason I decided on the Lightbridge is in affect it forces me to learn the night sky which I should do instead of the lazy GOTO option :)

Thats where I'm at. I'll look around a few more days and speak to people at astronomy clubs/events etc.

Thanks for the input thus far.

[Steffen]

On the topic of light loss through light pollution filters, has anybody got experience with the Baader UHC-S and especially Neodymium filters that are supposed to let more useful light through (while still cutting out most of the common streetlight spectra)? Are those effective and useful for smaller scopes (6-10")?

Cheers
Steffen.

[GH1967]

Thanks for asking that because I meant to.

Keeping it simple, can anyone name for me 2-3 simple "must have" filters by brand (maybe with a link) ideal for (hypothetically) a 12" dob in Sydney?

The purpose being of course to combat light pollution. :)

Thanks.

[norm]

Hey Mate,

My recommendation would be the NPB filter by Omega Opticals in the USA.

Looks like they sell via ebay these days:

http://cgi.ebay.com.au/NPB-1-25-DGM-Optics-Nebula-Astronomy-Filter-/310214737428?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item483a3d3e14


Comes in both 1.25 and 2" sizes. It covers a broad spectrum of what you can use it for.

If you search the thread, it receives many good reviews.

I don't use mine as much as I would like, but that's not to say there is anything wrong with it.....it more the hassle of screwing on/off from the eyepiece.

Cheers Norm

[Steffen]

I suppose getting 2" filters and screwing them into the 2"-1.25" adapter can reduce this hassle somewhat. After checking that none of the 1.25" eyepieces protrudes too far…

Cheers
Steffen.

[marki]

I have not tried the baader UHC-S but can recommend the astronomics CLS which cuts effects of mercury and sodium lights (most common street lights). I have found it to be usful on brighter objects through my 5" mak (F15), ok on most objects through my 8" SCT (F6.3) and great for the 10" ACF (F10) and 16" LB I once owned (F4.5). It is not good for small refractors 3.5" - 4.0" as it makes the object too dim.

Mark

[Suzy]

I was doing some research recently on filters and came across this terrific link- just about everything you need to know. Hope it helps.
http://pages.sbcglobal.net/raycash/filters.htm

[erick]

:thumbsup: Yep, David is the filter Guru!