need some advice regarding buying a new telescope

[neelam]

hi guys i have decide to buy a new telescope.the current one i own is a cheap 3.5 inch refractor that cant even show rings of saturn.

i have decided that now i will get atleast an 8inch,but i also want it to be cheap.like my maximum budget would be 400 dollars

i was looking at the following

Meade LightBridge Deluxe 8-Inch Truss Tube Dobsonian Telescope - Telescopes at Telescopes

what do u guys think is it worth it?and is it easy to assemble.

if i take to a desert will it get dirt on lense cause i see no tube?

why is so?

and also are there any alternatives to this in the same budget?

i want to see deep space objects lke galaxys,nebulas and cluster clearly but they may look small.

[neelam]

how about zhumell?it has full tube

[John]

Of the 2 scopes you list the Zhumell would be slightly better. It has the same optics as the Meade Lightbridge but the solid tube will mean it's collimation (the alignment of the 2 mirrors) remains good for longer, especially if you are going to transport it frequently.

The truss tube design (ie: the Lightbridge) only really has advantages when you get to over 10 inches in aperture.

John

[JamesC]

I'm a bit of a newbie, so I'm probably not qualified to give advice, but here goes anyway.

Are you in range of a desert?! Having a Dobson that you can take to a desert sounds like a really good idea to me! Do you get good transparency?

I agree with the previous post about the solid tube. A solid tube will cause you less trouble. As far as I can see the main reason for getting a truss tube is if space is going to be a problem for transport or storage, or if the tube is so large that it becomes a problem to handle (certainly not the case for an 8"). I have a 12" flextube and I can tell you that it is really easy to put up and down, although it is a difficult lift! One problem with truss tubes is that your own body heat can cause shimmering if the wind is blowing in the wrong direction. Also if there is any light pollution, a solid tube will probably give better contrast. Another concern with a truss tube is dropping something on the main mirror. I haven't done it and it probably isn't very likely but I do sometimes feel a bit nervous in case I accidentaly throw something in the 'bin'. For these reasons, I am considering trying to make a shroud for my 12". I imagine dust control is easier with a solid tube as you can just pop on the lid - but a word of warning there. Just as the mirror is the last thing to cool down, it is also the last thing to warm up, so dew has a tendency to recondense on the main mirror if you just pop on the lid after observing, but as you mention a desert, maybe dew isn't a problem.

By the way, I notice you were looking at an f6. I believe collimation becomes easier the slower the 'scope, so f6 is probably quite good if you are interested in planetary. Obviously with a dobson you are going to have to hand track, which will limit you a bit, but don't let me put you off a Dobson. I love mine!

Beware following my advice, as I am still getting into this hobby!

[neelam]

thanks guys for the advice but is it posible to get hold of a new 8inch refracto or reflector under 400 dollars?

and also can i view deep space galaxies and nebulas with 8inch dob?

[John]

thanks guys for the advice but is it posible to get hold of a new 8inch refracto or reflector under 400 dollars?

and also can i view deep space galaxies and nebulas with 8inch dob?

This is a good scope and well under $400:

http://www.telescope.com/control/product/~category_id=dobsonians/~pcategory=dobsonians/~product_id=08943

Yes, an 8" dob will show lots of galaxies and nebulae. Most will still look like fuzzy patches or blobs though to be honest - you will need a HUGE scope to see anything like the pictures you see on the web or in magazines.

John

[Castor]

I would also go for the Orion SkyQuest XT8 Classic Dobsonian as Jahmanson suggested. But if you can't see the rings of Saturn in a 3.5 inch Refractor, you must be doing something wrong, because I can clearly see them with my 2.5" refractor.

Or maybe you just meant it lacked detail?