"Odysseus" wrote in message
...
s wrote:

After many years of lying back in the grass gazing up, I think I have
finally outgrown my 7X50 binoculars. But what next? I have about NZ$1000
budget for a 'scope. I have read and understand the differences in the
types
of telescopes, refractor, reflector, and those funny "fold the light in
half" scopes (I figure the latter are out of the question due to price),
but
what do I choose? for NZ$895 I can get an 8" Dob
(http://www.astronomy.co.nz/pub/GS680.asp) or for NZ$995 an 8" Newtonian
(http://www.astronomy.co.nz/pub/GS600.asp), I could possible stretch my
budget to a 10" Dob, NZ$1195.

But what to choose? Should I even be looking at reflectors? should I
seriously consider a refractor? I fully intend to spend many hours
oooo-ing
and ahhhhh-ing over the rings of Saturn, are reflectors the right scope
for
this?

For planetary observing you generally want a long focal length for
high magnification, so the GS680 would be the better choice of the
two; although at f/6 it's still fairly fast, this will make it good
for faint DSOs as well. In smaller sizes a refractor might be more
suitable, but an eight-incher is a huge and expensive instrument;
since in general 'aperture rules', I think you're better off with a
reflector than a considerably smaller refractor.

Using the supplied 9-mm eyepiece with the GS680 would give you 133X
magnification; since a 'scope of this size should be capable of 400X
(under ideal conditions) you'll probably want to get a higher-powered
EP and/or a Barlow lens to take advantage of its aperture. The main
drawbacks of the GS680 as compared to the equatorially mounted GS600
are that it won't be as easy to track objects with it, and it will be
much more difficult and expensive to rig for 'go-to' capability, let
alone photography. But if you're considering the GS600 you should
thoroughly investigate the sturdiness and quality of its mount; if
the manufacturer has 'cut corners' on this component (if they
haven't, the price would seem to be quite a bargain) the instrument
will perform poorly no matter how good its optics may be.

On both models the single-ring finder-scope mounting may be a
problem; a two-ring bracket is generally easier to keep in alignment.
You might want to replace or supplement the supplied finder with a
Telrad or similar accessory.

--
Odysseus

Hey thanks for your comments Odysseus, I understand your concerns about the
quality of the mounts, that is something I have read up on too, one "expert"
advised spending as much money on the tripod and mount as the optics. How
would a novice like me be able to judge the quality of the mount?

Also, in you opinion, should I go the extra NZ$300 and get a 10" rather than
an 8"? Here is a link to the 10" (http://www.astronomy.co.nz/pub/GS880.asp)

These ATRONZ scopes are the best prices I have found here in New Zealand, in
my correspondence with them I have learned they are a venture by the
Auckland Astronomical Society, and they import the 'scopes, assemble, badge
them and market them in NZ. Other sources I have found for 8" Dobs are
NZ$4-500 dearer. I did question ASTRONZ on their pricing and they told me
because the are a branch of the Astronomical Society, they are not making
any great profit, merely serving their members and a little fund raising.
Story sounds plausible, but still doesn't assure a novice of the quality of
the equipment, especially the mount. What should I look for in a good Dob
mount?

Sorry for the long rant here, if you have persisted and read down to this
far, I humbly thank you, and would appreciate any and all feed-back.


Kind Regards,

Steve S