Newbie Telescope help

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?

Help?!?


Steve S

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

"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

I'm no expert, just another searcher for the perfect telescope. A
couple of things I've been grappling with though:

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)

Check out the size and weight of that 10". If you plan on moving it
much and are going to be setting it up yourself, that is really
something to consider. I'd love a 10 inch, but the size is just out
of my league at the moment.

As for the mounts, I'm shying away from the Dobs only because of the
lack of drive motors. The only drives I've seen for a Dob are very
expensive indeed. I'll admit that I'm a bit lazy, but I want an
object in the viewfinder to stay there without me making constant
adjustments.

Let me know what you decide on. I don't think my budget is too
different from yours and my astronomical experience is different only
in that I've been using 10x50 binoculars.

"s" wrote in message
...
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?

Help?!?
I think, both are capable of giving you some really good views of the sky.
However, you really need to 'handle' the 10", before making a decision (is
there any chance you can get somewhere and 'see' the scopes in the flesh?),
since though 'aperture rules', there is a second adage, that runs 'better a
smaller scope that is used, than a large scope that stays indoors'. Are you
competent at woodwork?. Generally, the GEM mount shown, is one of a family,
that works reasonably well, but tends to suffer from the aluminium tripod
being pretty wobbly. A solution to this, is to make your own wooden legs,
which work far better. Also consider that your budget, is possibly going to
have to cover a lot of other things (a couple of eyepieces, possibly a
Barlow lens, a planisphere, etc. etc..), so it may be 'better' to keep some
money in reserve. Note that at F/4, a 'coma corrector', may well become a
'required' accessory, if you want to look at wider field views. As has
allready been said, if your _primary_ desire is to look at planets, the
longer focal length models will 'suit' slightly better.

Best Wishes