I would recommend much study, deliberation and multiple trips to the
local astronomy club before investing in a telescope. You already know
you need to buy something that's not junk and (especially) that you need
a clock drive. It doesn't take much magnification at all before the
rotation of the earth causes objects to rapidly sail through your very
narrow field of view (if you can even find them in the first place).
The first thing you need to understand is that there are fundamentally
two different types of amateur telescope.
The first type is designed primarily for lunar and planetary observing
and (depending on the mount or optional mount) terrestrial observing as
well. Such scopes are characterized by long focal lengths, focal ratios
typically ranging from f/10 - f/16 and fairly high magnification.
Probably the most common and least expensive by aperture for this type
is a Schmidt-Cassegrain optical design. It can be used on a terrestrial
altazimuth mount or astronomical equatorial mount. It has the advantage
that the optical tube is short and the eyepiece doesn't move around much
which makes observing easier.
The second type is designed for what's called "deep sky" observing which
is relatively low power, short focal length and large diameter with
focal ratios from about f/4 - f/5.6. You might call it a light bucket
more than a magnifier. The most common of this type and least expensive
for amateur use is called a "Dobsonian". This type is inexpensive since
it uses a simple, wooden altazimuth mount and, since it's low power
dispenses with a clock drive. But be sure to use one before buying one.
Like the Newtonian below the eyepiece moves around a lot and, with a
large scope, you might find yourself on a ladder or stepstool at times.
Maybe as a third type is the common Newtonian reflector telescope which
tries to be a compromise between the two and is usually an f/8 design.
The main companies selling scopes in the US are Celestron
<http://www.celestron.com/> and Meade <http://meade.com/>
But there are lots of small companies that make scopes. I suggest you
go to wherever you can find a large number of magazines for sale and buy
a copy of "Sky & Telescope" magazine not only for the astronomy content
but the advertising content. <http://www.skyandtelescope.com/>
My own telescope is a 1974 Celestron 8 (8" diameter mirror) identical to
this one except that this one does not use the original tripod.
<http://www.ebay.com/itm/Celestron-C8-2000mm-f-10-telescope-with-tripod-and-accessories-/230967532792?pt=US_Telescopes&hash=item35c6bcdcf8>
This one comes with a lot of eyepieces (expensive) which may explain
the asking price.
This one
<http://www.ebay.com/itm/Celestron-8-Telescope-2000mm-/281098570320?pt=US_Telescopes&hash=item4172c7ca50>
has a starting bid of only $700 but it's in rough shape. Fairly dirty,
no tripod, only one eyepiece and possibly some parts missing. Like
camera lenses, old scopes can suffer from fungus on the glass if stored
in a damp environment.
Another thing you have to be concerned with (if you don't have an
observatory) is weight. The optical tube alone on the Celestron 8
weighs 25 lbs. The mount/clock drive is probably about the same and the
tripod another 15-20 lbs. Consequently I haven't used it in many years.
Who is Walt who used to say; "There's nothing photogenic more than 500
yards from the car."? Consider a camera that weighs 70 lbs.
Chuck Norcutt
On 4/26/2013 12:40 PM, Paul Braun wrote:
> I've always wanted to do some astrophotography, and my wife surprised me by
> telling me that she's wanted a telescope since she was a little girl.
>
> Problem is, I know I won't use it heavily enough to spend a bunch of money
> on one, but I also don't want to buy crap. I just need something decent
> with a tracking mount. Maybe I should find the local astronomy club and
> ask for recommendations. Maybe someone's upgraded and has a decent used
> scope for sale.
>
> -- Paul Braun
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