Dob/SCT, cheap/expensive?

[Solanum]

Thanks for the replies to my previous, rather niave as it turns out, post. I now have a much more specific set of options!

1) Buy a cheap 8" Dob, e.g. the ones from Andrews, and see how much viewing I actually manage then go for an expensive 8" SCT with the works later if I think it's worth it.

2) Buy a Meade ETX 105 or similar with all the electronic gizmos now.

3) Buy a good 12" Dob at around the price of the ETX105.

4) Look around for a second hand 8" SCT

I have great skies here in Mildura, rarely any cloud, some glare from local streetlights, but no skyglow. We do get dust in the air though. However, I also have two small kids (who I hope to get interested in astronomy in coming years) and another on the way, so my observational time is going to be limited.

Thus the ETX105 appeals as it will do all the hard work for me and I should be able to see something! On the other hand, the additional power of the Dobs is very appealing. Option 4 is least so, because I don't feel confident in being able to judge whether a scope is on it's way out or not.

I would very much welcome opinions on which option to go for, bearing in mind my comments above. I'm slightly leaning towards option 1 - would that be a mistake?

Thanks!

[janoskiss]

If you're thinking that you will get better views with the SCT because it's more expensive you will be disappointed. Those inexpensive Dobs perform very well. Bang for buck they are, no kidding.

I don't like your option #2 - small aperture means you will want to upgrade after few nights of observing, or #3 - 12" is too big for a first/only scope IMO.

[jase]

I fully agree with Steve's comments. Also, I wouldn't rule out option 4. Shop around, you may find some reputable people here on IIS that no longer have used for an medium aperture SCT. Who knows, you might pick up a goto version if that is what you desire.

[AstroJunk]

I recon the 8" LX90 has got to be the best starter scope ever (if you are willing to part with some dollars!). If you can't find one with a price tag to suit, go for a dob.

What ever you do, get at least 8 inches. Consider the intelliscope dob from Orion (sirius optics stocks them), they have the a push-to computer built in at a very reasonable price (considering the cost of after-market ArgoNavis).

What ever you do, get at least 8 inches. Haven't I said that before?

What ever you do, get at least 8 inches. There I go again!

[stephenmcnelley]

With the etx you will view the moon and a couple of planets, the brightest of the star clusters and two or three of the brightest galaxies then that would be about it.

[iceman]

I agree with Steve also - the 8" dob will give you better views (imo) than an 8" SCT.

The SCT has other advantages, like being potentially more portable (shorter tube) and usually goto-fitted on a fork mount.

So rather than narrow your choices to 8" dob or 8" SCT, think about whether you really want GOTO or you're happy to use star charts to find the objects you want to see.

Goto and tracking increase the price considerably, and take longer to setup than a dob. But it is nice to be able to push a button to take you to an object.

Dobs can be fitted with DSC's such as Argo Navis, which will give you "push to" instead of goto, so you can still find those elusive objects.

What's your budget?

[Solanum]

Thanks again for the replies. My budget will be about $1500. However, if I spend that I won't be buying another scope for quite some time. As I mentioned my observing time will be limited, which is why I was wondering if an 8" dob of the $500 to $600 mark is the safer bet. If I find I really want something better then I might be able to justify a bigger budget than $1500 later (but can't now - not for a first scope).

My interest in an SCT is not that I think they'll be better than the equivalent size dob, but because I've been interested in photography for many years and would like to extend that to astronomy.

Looks like I'll ditch option 2. As for option 4, I'm sure there are reputable folks around, it's just that I'm not in a position to judge! Plus being in Mildura makes it difficult. Though there is a Mildura Amateur Astronomy club and I will go along to their next open night.

If 12" is really to big for a first scope (I know they 12" dob is BIG), then perhaps my options are more:

1) cheap 8" dob at $5-600
2) good quality 10" dob at under $1500
3) second hand 8" SCT

Are the cheaper dobs significantly worse viewing (inch for inch)?

[gbeal]

Dob for me. What about the new LightBridge series, I thought the 12" was about $1400?? That would be my pick.
If you want an SCT (not including a fork mounted one), and don't want to be frustrated with it, then figure at least as much again for the mount, same for a refractor. The mount tends o be the most expensive and least thought of part of the equation.

[iceman]

There really isn't a "cheap" dob and a "good quality" dob in our market. All the dobs you buy from the shops are good value, and come from 1 of 2 manufacturers (GSO or Synta).

Yes you can spend MORE on a dob, but that usually means the retailer is not discounting, NOT that you're getting a better quality product. A "good quality" dob usually means a custom-made truss dob with a premium mirror. That's much more than your $1500 budget.

So i'd discount your option 2 above as well.

If you want to get into photography, your budget will be blown straight away.

If you don't know how much you'll use it, stick with the dob to start out with - although make sure you understand how to find the objects, how to collimate, etc. If you don't use it much, and when you do try to use it you can't find anything interesting to look at, or the views are fuzzy/blurry because you haven't collimated, then you'll think you bought a dud or that astronomy is not the hobby for you.

The dobs come in sizes from 6" up to 16" (sometime next year). At the moment the best ready available sizes are 8", 10" and 12". Each have their pros and cons, in portability, aperture, cost, etc.

[casstony]

My 2 cents:
if you can sometimes observe with others get a 10" dob. Other observers can help you with finding objects and the 10" is not too hard to carry and is easily shifted around the yard by trolley.

If you observe solo get a used 8"LX90. It can do a guided tour of the sky and show you a dozen objects in as many minutes if you want. You won't be feeling discouraged by not being able to find things.

[Solanum]

All right you've persuaded me! I think I'll go for an 8-10" dob at the cheaper end of the market. I can then use the money I haven't spent for eyepieces etc. when I feel the need, or if I get totally bitten by bug put it towards an LX90 or similar one day in the future.

I'm hoping I won't find it to much trouble finding things to view. I am a scientist by day and have always been reasonably good technically. I used to be pretty familiar with the northern hemisphere sky when I was younger (though not finding things through a scope...), so hopefuly I can pick up the southern hemisphere sky without to much difficulty.

I'll join the Mildura society too, that should help.

I'll just add that I've found this forum very helpful, friendly and positive, both in my own contact and browsing other threads.

[stephenmcnelley]

Hope you enjoy your choice of scope Solanum, at least with a Dob your effective viewing time outside is maximised as there is almost no setup time, and finding objects yourself is very rewarding, with a goto scope it can become boring....

Oh and with the money you save it might be worthwhile to consider some more capable eyepieces than the super plossls and reverse kellners etc that usually come with these scopes, EP's with a wider field of view seeming you have to track objects by push/pull.

As you have probably seen there are articles on this website that detail how to cheaply and conveniently transport these types of scopes in and out of the house without back strain, and how to maintain and care for them.
The search function on the toolbar above is an excellent tool for answering questions too.
The Mildura area would be excellent for deep sky viewing!
have fun.

[matt]

Getting a dob?

Get a Telrad:D

[swannies1983]

Sounds like the consensus is an 8-10" Dob which is a great choice. I started off with a el-cheapo 60mm Tasco refractor bought as an Xmas present from Cash Converters. I had many hours of enjoyment with it and was able to "glimpse" some surface details of Mars back during the '99 poor opposition.

I then wanted to upgrade and I was orginally going to get one of those 114mm reflectors but I was soon persuaded to get something bigger. I didn't want a full on mount, nor GOTO so I kept my eyes on an 8" scope. I eventually got around to buying the 8" just before the 2001 Mars opposition. While the dob doesn't have tracking, I actually took some nice shots of Mars (and eventually Jupiter and Saturn) using an old 1970's model SLR camera I picked up for around $100 at Cash Converters. I eventually moved on to the Phillips Toucam which has produced better shots of the planets.

The "new addition to the family" is my Tal 200K on an EQ6 mount. While the Tal 200K has the same aperature as my Dob, it shows a lot more detail (better contrast) compared to the Dob. A digital SLR camera is next on the list.

Anyways, I highly recommend the 8" Dob as I still use it today and plan to put it on the EQ6. I don't know how much of a difference a 10" makes over an 8" though.

Oh, just to add....while GOTOs are great, there is always a sense of satisfaction when you find and identify a galaxy, globular cluster, nebulae etc by yourself :)

[ving]

welcome abaord :)
you seem to be sorted now. I have a 8" dob... well its an ex-dob. i now have it mounted on a heq5 equatorial mount. this could be used for planetary astrophotography easy and may be a consideration for you too.

[Solanum]

Swannies, I've been an SLR user for 20 years and I wouldn't consider any other type of camera (well not unless someone donates me a Hasselblad!), thus my initial desire to use my 350D for astrophotography. However, I can see that that might be a step too far initially. I also think it will be useful to me to find objects by myself, rather than relying on GOTO. Incidentally, the 350D is now replaced by the 400D, virtually the same camera, but you might find that in the coming weeks the 350D can be found at stock clearance prices.... After many years of film SLR photography I am not disappointed in the 350D.

Well, now I'm looking forward to spending the next few weeks deciding exactly which dob to get!

[swannies1983]

That's what I plan to do but on my EQ6 mount. Have you imaged through this combination? I have read up somewhere that people have found it difficult to achieve enough focus with reflectors :shrug:

Also, is it correct that you need to keep rotating the tube when you slew the scope to other positions? I read up that you can wrap some tubing around where the rings are so you can easily rotate the tube without impacting upon the balance of the system

[ving]

i have only imaged the moon and planets with a webcam (lpi). to connect a dslr or slr you do need to move teh primary up teh tube a bit, but plenty of people have done this here so if you needed a hand then just ask :)

[sejanus]

solanum,

I wouldn't be worried if you don't have a computer. I bought an EQ6 which obviously does have one, but I was having problems with it - in the meantime I was going to stuff manually myself with the aid of a telrad and my laptop (to see where stuff is in a program like starry nights) and it was a heck of a lot easier than I thought it would be.

[sejanus]

hey ving can you post a pic of what it looks like on the mount?

[ballaratdragons]

With my Toucam I haven't had to move the mirror at all.

The only time people prefer to rotate the OTA in its mount is for visual use so they can see in the EP. For Astropics with a Toucam it doesn't matter what angle the Focuser is at. For DSLR's it might, dunno, I ain't got one.

[swannies1983]

I have one of those Olympus OM-1 SLR cameras. Like I said, I picked it up for $100. The only problem was that the the handle to wind the film was broken so it takes a little more effort to wind the film back. Apart from that, the camera works really well!

Yes I have been keeping an eye out on the price of the 350D following the release of the 400D. Are the 350Ds cheaper over in Singapore?

[Solanum]

Dunno about Singapore, in my looking around the dSLR prices didn't seem to vary by more than a $100 or so.

The OM-1 is an excellent camera - pity your winder is broken. You could probably get that repaired if you find a suitable shop. Up until the advent of affordable dSLR the OM-1 was still a sought after camera. I still have a Pentax K1000, similarly all mechanical beast and very solid.

It's amazing what the Canon and Nikon dSLRs have done to the film market. The photographer at my previous place of work had a pro Nikon outfit which went from being worth $6k second-hand to about $1500 in 18 months.... he wasn't happy about it!

[sejanus]

solanum - i know that feeling! I had 2 x Nikon F5's which went from being around $3300 each to prob $700 or so each in the space of a few months when the d1h / d1x hit market.