Hi Jowel & Bern,
Point 1
Dobsonians give the largest sized aperture for the lowest cost. For visual observing the largest sized aperture you can handle/transport & afford is recommended. Very quick to set up as well - plonk tube into the base and your set, thereby making them an ideal beginners scope in general.
Point 2
Realise this now... if this is your first telescope, it won't be your last. You will more than likely upgrade; most of us do (be it for either tracking, larger aperture, or astrophotography). Having point no.1 in mind, use your first scope to cut your teeth on and learn. As time progresses, trust me, you will get a better understanding of what it is you want. I myself went from a 6" dob (my first scope), to a 10" dob (2 wks ago) within 6 months. During this time, I learnt that my interest not only intensified, but I was also eager to pursue visual observing. A decent time frame also allowed me to be more educated on the accessories required for the scope. Learn how to handle your scope first, in it's most simple basic form, then add.
The 6" is easy to carry/transport. Though I ended up putting wheels on the base, so I could just drag it everywhere in one unit. The 10" is around 25kg (complete unit). Currently mine is getting wheels attached to the base with a handle that I can drag it by. Bigger and more wheels required on this one. Or you can do what most people do and use a trolley. Believe it or not, the weight is the same for collapsable and solid tube- it's all about portability really. Don't forget, as Liz mentioned recently in a similar post you will more than likely need to get a shroud for it which can be costly (or get someone to make one). Some people manage just fine without them, others complain they need it as stray light gets in. As for the managability of the 8" I can only assume this falls between the two scopes I have used, so I would gather it wouldn't be difficult.
There is a considerable difference in light gathering between a 6 & 10", that quite frankly I didn't expect. Everything is brighter, stars that were once feint are now luminous, coloured stars pop out everywhere. Globular Clusters are more resolvable. That being said, I really do believe my 6" still had plenty to do and see... it served me well, including viewing M104 (The Sombrero Galaxy- 30 million L/Y away- not bad, albeit feint). A lot a 6" is capable of, just a bit feinter. I could resolve globs as well- just took a bit more time to stare them out. My eyes got better at extracting detail. I got a whole magnitude difference (that's 2 and 1/2 times more light) than my 6", if that's any help gauging the difference for.
With what Chris just said, $449.00 for a collapsable dob is a truly fantastic price. But, work out if will require a shroud. You can buy the solid 8" tube dobs for only $489 at the moment from Ozscopes. Their service is fantastic, many (incl myself) have dealt with them and have been very happy with their efficiency and knowledge.
Have a look
http://www.ozscopes.com.au/telescope...nian-telescope
The following two links are from the Articles & Projects section on the blue menu bar to the left of the screen. There is plenty of information in this menu section to learn from- make it your next best friend. The following is a beginner's guide to choosing your first telescope - part one:
http://www.iceinspace.com.au/63-260-0-0-1-0.html
Then, commence reading part two:
http://iceinspace.com.au/63-261-0-0-1-0.html
Here also, is a link that may be helpful- it is a telescope simulator which will enable you to get an idea of the views you will expect to get through different scopes and eyepieces. It's a lot of fun actually ...
http://www.telescope-simulator.com/i...d=45&Itemid=57
Lastly, I would like to leave you with some great advice from Ausastronomer (John Banbury- a very knowledgeable gentleman). I’m sure he won’t mind if I quote him here…..
"Some of these cheaper scopes have poor optics, poor finderscopes and even poorer mounts. You will find them to be nothing more than an exercise in frustration. You will not be able to find very much, when you do find something you won't see very much and what you see will not stay in the FOV very long and you will then spend the next 30 mins trying to re center the target. After 2 weeks of frustration the telescope will spend the next 2 years unloved in the corner of the closet, the loungeroom or the garage. Avoid any telescope sold by any store other than a store that specialises in astronomical telescopes. Avoid stores like Dick Smith Electronics, Australian Geographic and Camera stores. These stores carry a very small range of astronomical telescopes and what they do carry is nothing more than junk, in most cases. Experienced people call these XTT's. Short for XMAS TRASH TELESCOPE's. Further, the people who work in these stores might sound like they know what they are talking about when talking to someone who is a beginner, but truth is 99% of the people working in these stores don't know one end of a telescope from the other themselves. Some of these small cheaper scopes are very difficult for an experienced person to use, let alone a beginner.
If you can stretch the budget a little further I would recommend a 6"/F8 dobsonian which you can buy from Andrews Comms for about $350. A scope like this will show you 500X more than some of these other "toy" telescopes and most importantly will be infinitely easier for you to operate and find things in. You want to foster your interest in the hobby, not leave it out of frustration after a short time period."
Cheers,
John B.
Oh, I just read another post you added Jowel. Okay...
The dobs do require more frequent collimation. Especially each time you go up in size. In the 6 mths I had my 6" I never had to collimate it. I've read that with an 8" it is required more frequently, and required even more so frequently with a 10".
Regarding eye pieces, I did notice I got better & heavier ones with my 10" than I did with my 6". But they are still quite ordinary. But initially do the job just fine. Get used to your scope and get educated before you go down this path. Worry it about it later (this includes barlowing).
Scopes require a cool down time (from 30mts for a 6" to an hour with a 10"). This brings the scope to the same temp. as the outside air. All you have to do is take your scope outside and leave it for this time frame before viewing.
I've read plenty of times that collapsable dobs hold their collimation quite well compared to solid tubes. Don't be scared by collimating, once you learn it, you can have it done in a couple of minutes and it will become second nature. Don't let that stand in your way (I've never done it- I'm lazy and leave it up to hubby for now). Laser collimators make things easier.
Skywatcher, Saxon, etc are apparently all made from the same factory- just rebagged.
Okie dokies, I'm done, my hands are sore from all this typing
Enjoy boys- your in for the time of your lives once you get your scopes!
Regards,
Suzy.