Which Dob For Me? Collapsible or Full Tube?

[gpb (Chris)]

My journey so far has taken me from a SCT to a Dob. What do I like about the Dob? Well for starters it's cheaper for the size of you can get, they set up quicker to view, they are very popular and many people have them, so basically you get more bang for your buck.

OK then, now I've reached the stage of the journey where I've narrowed it down to a 14" Skywatcher or 16" GSO. I know my wife is picturing a small telescope on a tripod, she is going to freak out when one day she walks into the back yard and sees what will look like a canon.

Anyway, although I mentioned SW/GSO will be good, I'm getting another thought as to which way shall I go - Collapsible or full tube?

What are the pros & cons on both?

I have a feeling that the full tube is better and for some strange reason (mind you I know nothing about telescopes) it will require less maintenance.

There are two things that put me in favour of the full tube over the collapsible and that is it will require less collimation and less dust gather? Is this true people? I know the disadvantage of a full tube is that it will be heavier and storage/transportation may be a worry but I think I OK wiith that.

What are you thoughts people, Full or Collapsible, 14" SW or 16"GSO?

[Stu Ward]

If it's your first scope then 14-16 may actually be too large. I would personally recommend you look at an 8-10 inch for starters. You could actually then go for a goto dob which will help you find those difficult objects.
I have heard that novices that go for the big scope off the bat can have a rather bad experience. This leads to a pretty short lived astronomy hobby



Stu

[Osirisra (Ken)]

I would have to agree with Stu, a 14 or 16 is going to be one hell of a big first scope. I mostly only use my 14" when I'm going out to a nice dark site on a really good night to get the full benifit of the light grabbing power as it is can be a mission each time to transport and set it up.

I don't know what kind of car you have but you are most likely not going to be able to transport a full tube and you will have to pull the base apart as well. You may think that you will be all ok and it not too big or heavy but after a few times you will soon realize how much of a hassle it can be and you will tend to not want to be bothered as it becomes a chore.

Around the 10" mark with goto would surly be a better and more managable option and you will use the scope alot more. I have the collapsible 14" and even so it is still a bit of a handleful to move about with out a trolley. As the very wise saying goes, "buy a scope you will use..."

Have you been out to a party/group/club yet and checkout the different scopes? even go into your local dealer and you will be supprised how big a +10" is.

I two was a little concerned about the choice of either a full tube or not but I'm glad I went with a collapsable, I just made a shroud to suit that works really well to stop stray light, dust etc. The designs of the non full tube systems these days are very good and you will not need to stress about flex, dust, or collimation, if you look after the ota it will look after you

[GraemeT (Graeme)]

Originally Posted by Stu Ward

If it's your first scope then 14-16 may actually be too large. I would personally recommend you look at an 8-10 inch for starters.
Stu

I have the 8" collapsible Skywatcher and it will fit comfortably into my car and is just about as much as I can handle by myself.It is easy and quick to set up & holds its collimation well. It goes out to club viewing most Friday nights. There is a 12" that turns up but it needs to be transported in a van. I would only consider a biggie if it was going to be on a pier or somewhere you can get a trolley of some type to cart it a short distance.

[barx1963 (Malcolm)]

I have a 12" solid tube and I had to build a trolley to make moving it from the hose to the backyard feasible. The 14" and 16" are BIIIGGG scopes and you really need to see on to appreciated how big and heavy they are.
Personally I find the issue with size is not getting it out, it's putting it away. At the end of an observing session spending 15 minutes carting all the bits inside is alittle daunting when its 2am, about 0 degrees and everything is wet and covered in dew.
To be honest you will enjoy your observing more with a smaller scope (8' to 12" max) and for the first 12 months there are so many bright targets to see that look just great in a moderate scope you will have plenty to look at.

[gpb (Chris)]

Well I did say that I know nothing about telescopes guys and thanks for the feedback. My friends are not interested in astronomy, I do not know anyone who has a telescope so therefore I'm going in cold here without seeing these things in real life instead of viewing them on the internet.

I just thought big is better, but I really have to see these things to work out how easy they are to set up, i.e physical effort to take it out & bringing it in.

Tomorrow I'm going to a store to see them for the first time, I'll let you knwo how I go.

[norm]

My first 'real' scope is a 14.5" SDM. That said, I was fully conversant of what I was getting and this was planned for a lonnnnnnnnnnnnnng time.

The collapsible scopes do make transporting much easier and I'm not even sure you can get solid tubes in the 14 to 16" category. (16" in sonotube, but years ago).

Back to your intial concerns:

Collimation - nor hear nor there. Once you learn how, its like riding a bike you don't forget. 2ndly, once you know the basics, its only takes a minute to do each time. So really, it shouldn't be a factor in deciding between a solid vs collapsible. The way I see collimation is like riding a bike witha semi inflated tyres. Wouldn't you rather spend the few mins. to pump up the tyres so you know you'll get a decent ride, as opposed to going for an hour or to, then regretting not pumping it up? Imagine spending 2hrs at night viewing only to later decide to check on collimation and notice you were slightly out and then tweaking it suddenly made a difference?

Dust: When your not using the scope, you will have some form of a cover over the scope or just covering the mirror. A makeshift cover from an appropriate size plastic pot plant lids does the trick. Just make sure it doesn't sit on the actually mirror surface. Therefore dust shouldn't be an issue. During observation you may or may not have a shroud to cover the scope. Will excess dust gather on the scope ? - personally I don't think so. If it does, its not going to be all that different to a solid tube. At the end of the day, dust will form and generally does not impact the viewing quality. Over time (2 years+), you may need to wash the mirror (see threads on how). Again, not a big deal.
If anything, an open truss design scope may allow dew to form a bit quicker on the mirror surface on moist cold nights - a shroud will help to delay this.

At the end of the day, neither of these 2 concerns should be a major issue.
Things you need to consider are:
1. how comfortable are you at carting this size scope around?
2. are you ok with assembling, disassembling after use - especially after a long night.
3. Will you use it more, or will something in the 10-12" be realistically more practical?
4. Try to get out to some observing sessions with others to get an idea and feel of the scope. Photos don't do things justice and it could be a good reality check. (not trying to negative here, just want to ensure you end up with something your happy with).
5. Will you be transporting the scope, is there enough room to fit scope, acessories and family?

It's too easy to go bigger cause everyone goes on about aperture, but when it becomes a chore to lug the thing out, it can put you off the hobby.

Good luck mate with the decision.

Norm

PS: I'm totally happy with the size of scope. But then again it is an SDM

[floyd_2 (Dean)]

Just thought I'd throw another contender into the mix. Have you considered an Orion XX14i or XX12i? I have the XX14i and love it. I would call it just manageable for one person if you were going to take it to dark sky sites. The XX12i would be very manageable. Both have a push-to computer which makes finding anything in the sky a breeze. As some of the others have already noted - buy a scope that is easy for you to set up / put away etc. It's no good if you have to think whether it's worth the hassle of setting up each night.

With my XX14i, I roll it out of the shed, put it up on leveling blocks, tweak collimation (2-3 minutes so far) and then walk away for an hour while the mirror reaches thermal equilibrium. It's dead easy.

If you're only going to observe from home, then there might be things that you could consider to make set up / putting away easier, like a dedicated shed and observing area, a cart / wheels for your scope etc. Certainly the XX14i and XX12i have good mounts that pull down to quite a small size if you intend to drive to dark sky sites.

I remember almost buying a 16" Meade (full tube) many years ago when they were new on the market. I will always be glad that I reconsidered, as the scope would have just been too big for me and would have led to decreased observing due to the increased hassle of man handling it everywhere. Certainly truss tube scopes have made larger apertures a lot easier to handle. I still think 14"-15" is about the maximum that I could ever comfortably handle on my own.

Best of luck with your decision.

Dean

[barx1963 (Malcolm)]

Hey Chris, good to know you are going to a store for a look. Of course they may not have any really big scopes (12" plus) but it should give you an idea. Best bet is to get along to a club night or star party. The Snake Valley astro camp near Ballarat is only a month away and I will be there and I am sure there will be other bigger scopes. Paddy should be there with his 16" and maybe others. The thread for the camp is here
http://www.iceinspace.com.au/forum/s...ad.php?t=71024
All of us would be happy to show you the views through our scopes to help you make the right decision.
You are right, all other things being equal, bigger is better, but the best scope is the one that gets used!

[gpb (Chris)]

Yep, once again all of you have really added some very important points and funny enough I realised that 14" & 16" would be way to unmanageable.

Went to Bintel yesterday and they had a SW 12" Flex Dob, and a 10" & 12" full tube Bintel GSO Dob. Immediately it hit me that anything bigger will be hard to get my telescope in and out of the house on my own.

I have set my sights on their 12" GSO. I was in the shop for nearly 2 hours, the salesperson was very helpful with answering all of my questions. They compared the Bintel GSO with the SW Flex Dob and I have to say the Bintel mount felt better and did not stick or make any noise when moved around, it had a fan and had a right angled finder, and it was cheaper.

They explained in depth about collimation and the different tools to assist in collimation. I found the laser collimator (sp ?) was vey quick and easy. They showed me a number of different angled lens trying to make me understand what they're used for, however with my untrained eye I could just make out the difference.

So, 12" Bintel GSO, standard lens set (can't remember which ones), filters including moon, laser colimator, a 2011 astronomy book with some very helpful data that's eliminates time searching on the internet & stellarium and one of those dial type star charts, all for just under a $1K.

Was I happy with this? Yep. I started this journey wanting to spend $3K and I have $2K to spend on lens , well not yet anyway. I haven't purchased it yet and have been stewing over the decision to purchase it since yesterday and the little voice in my head says go for it!

I think I may be star gazing tomorrow night. I'll let you know how I go because I bet no doubt I will be seeking further assistance on here and to share my experiences with the wonderful world of astronomy.

[barx1963 (Malcolm)]

Go for it Chris. The GSO (or Bintel) 12" is the scope I ended with and it is one of the best scopes around. I made a little trolley that I use to transport in and out as the OTA is quite hard to Handle. The thread describing is here http://www.iceinspace.com.au/forum/s...ad.php?t=47433
One other thing I have done is made up a couple of straps with velcro that wrap around the OTA to make carrying easier. I'll post a photo when I get around to it! Also you may find the azimuth motion is fairly "loose" so the scope moves around a bit too easily especially in the wind. This is easily fixed with a couple or 3 of those felt furniture pads they sell at the hardware store between the 2 plates of the base.
I assume by "lenses" you mean eyepieces (or EPs for short). The scope will some with a couple, according to the website a 26mm and a 9mm. These should be all you need to start with. You will find the 9mm hard to use as the exit pupil and eye relief are quite small, so the 26mm will spend a lot of time in the focuser. Don't spend money on expensive EPs just yet until you know what you want. When you do feel like spending some more have a look at the 24mm Televue Panoptic. Probably the best value for money general EP out there IMHO.
The Astronomy 2011 book is a good starting point, but once you get into it a really good atlas is essential. Uranometria 2000 is probably the gold standard but is abig publication. Sky Atlas 2000 is the other choice and I am a big fan of the Cambridge douple star atlas as a general use atlas. All these are available at Bintel. Try and get yourself to a camp or club night so you can learn some of the finer points of star hopping (and also to check out some EPs!) Try and get up to Snake Valley next month if you can.

Malcolm