NetNews Usenet Archive 1992 #16/NN_1992_16.iso/spool/sci/astro/8481

Internet Message Format | 1992-07-30 | 7.2 KB

Path: sparky!uunet!usc!rpi!bu.edu!dartvax!Frederick.A.Ringwald
From: [e-mail] (Frederick A. Ringwald)
Newsgroups: sci.astro
Subject: Re: Help on first scope
Message-ID: <[e-mail]>
Date: 30 Jul 92 10:49:58 GMT
References: <[e-mail]>
Sender: [e-mail] (The News Manager)
Organization: Dartmouth College, Hanover, NH
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In article <[e-mail]>
[e-mail] (Clay Babcock) writes:

> I am looking for any input on buying a first telescope.  I would like to
> keep the $$$ outlay under $750.00.
> Some questions come to mind:

This question again. It's really impossible to give you a definitive
answer without knowing you and your situation.


> Buy new v. used?

That's up to what you can find. If you can find a widow(er) selling off
her (or his) departed spouse's lifetime, cherished equipment for
ridiculously cheap, because she (or he) doesn't appreciate it, go for
it - although you are allowed to feel sorry for this person. Same goes
for the too-easily-discouraged hapless beginner who saw one NASA
spacecraft image of Saturn and promptly plunked down $3000 for what
would be a very nice instrument in hands guided by skill and knowledge
(in this case, you are allowed to feel scornful, but keep it to
yourself until you get out of earshot). Just make sure you know what
you're getting: a crappy department-store telescope with awful optics
and a mounting that vibrates so much it gives you a headache is still a
piece of junk, even if it's half off.


> Catalog v. Local store?

Department stores are to be avoided: people in the toy department don't
know optics, and they sure don't know astronomy. Camera shops can be a
little better, but often only a little. Avoid especially anyone who
advertises magnification as the be-all characterization of astronomical
telescopes, especially if it's absurdly high (over 200x). Magnification
can be changed with just a different eyepiece; plus, turbulence in the
Earth's atmosphere limits how big you can magnify anything and still be
able to see detail. Who wants a large image you can see no detail in?


> Refector v. Refractor?

Again, it depends on you and your situation. Well-made refractors (note
especially, "well-made") are superior for high-magnification,
high-contrast visual observing, as with planets, double stars, and
bright nebulae and galaxies, but they tend to be big and long, and
therefore unwieldy.
Big, unwieldy instruents of all kinds tend to sit in closets collecting
dust, because they can be a real pain to take apart, take outside
carefully in several trips, and put back together in the dark. By that
time, you're too tired to observe, or enjoy it.

Refractors can also be amazingly expensive. The aperture you can get,
practically, also tends to be small: 16" reflectors are not uncommon
among serious amateur observers, these days, but a 16" refractor would
be one of the largest in the world.

Even so, if I had $$$, which I do not, my instrument of choice would be
a fine, expensive antique 10" Alvan Clark refractor, with its own
observatory to go around it. Note that this is a very stationary thing!
This choice is based on my personality, and what I like to observe in
my spare time. Since I'm already a professional astronomer, photography
is low on my list of priorities; matching what I'm privy to elsewhere
would cost millions, and why bother, anyway, if I'm already privy to
it? I'd want something for casual observing with my friends, most of
whom don't know too much about astronomy, and so would not be impressed
by anything that's hard to see, particularly not if it's faint.
Therefore, I'd stick with planets, the Moon, good double stars, and
bright Messier and NGC objects. I'd get an equatorial mount, so I could
use setting circles, because I like to use them. (Some people prefer to
star hop, which would make setting circles extraneous; what do you
like?) An equatorial mount would be handy for some casual 35mm
photography, too, whenever I felt like it.

A toy like this would cost about $50k, complete. I am unlikely to come
into that kind of money in the foreseeable future, so I'd settle for a
Genesis on a good mount, for about $4000; this is portable and very
nice, although still expensive. For the Milky Way, I could go for a
pair of absolutely gigantic 11x100 binoculars, which absolutely require
a mount: this would be $2000, easily, although I am unlikely to come
into this kind of disposable income anytime soon, either.

Come to think of it, I've had many enjoyable times observing with a
just-awful department-store telescope: because I knew what to make of
it. This hobby requires skill and knowledge, which really is fine: part
of the fun, a never-ending part, is to acquire this skill and knowledge
for yourself. With my department-store telescope, I could just pick it
up and drag it down the stairs of my apartment and not care too much if
I bashed it against the wall once or twice, and plop it on the front
sidewalk 10 miles from downtown Chicago, and look at the Moon and
planets. The neighbors enjoyed this, too, once they could see I wasn't
looking in windows. It's all up to you. (See also my comments about my
favorite observing, below.)

> What type of mount

Dobsonian telescopes are strictly altazimuth, and are very popular for
visual observing. Equatorial mounts are useful for photography,
although they are expensive. What's it worth to you?

The best thing I can say about any mount is: buy quality! Mounts that
shake and vibrate invariably give me a headache, just like observing
through clouds. A mount *should* hold your telescope STEADY! They
should also be easy to control, too, with coarse motion, often called
slewing, plus some kind of fine control, to make it easy to move just a
little bit, smoothly and not jerkily.

> Rich field?

Not unless you like rich-field observing. It really helps to have a
dark site to do this. Your neophyte friends will expect the Moon and
planets, of course, but still, my very favorite observing is still
*naked-eye* of the Milky Way on a deep, DARK night. I do this every
chance I get from the deck outside our 1.3-m or 2.4-m telescopes on
Kitt Peak, while the autoguider is on and I'm doing a long exposure
(see the Letters, p. 12 in the 1992 July issue of Astronomy magazine,
for more I wrote on this).

>
> Someone has refered me to the Edmund Scientific Astroscan 2001.
> Any opinions on this?

Bleah! How do you hold that blasted round thing steady? Also, I have
never been impressed by the quality of Edmund's optics. They are
portable, however, so it's easy to take one to a garbage can.

Tell you what: why not hang out at star parties at your local astronomy
club, so you can try things out and see what's what? Sky & Telescope
magazine publishes lists of local clubs, once or twice a year. Check
out back issues in the library. Also, Orion has a nice catalog and a
good reputation: get any issue of Sky & Telescope or Astronomy, check
out their ad, and get their catalog. Good stuff, at not bad prices, and
I promise I do not work for them and am not getting any money from
them: I'm just a happy customer.

Fred Ringwald
Department of Physics & Astronomy
Dartmouth College
Hanover, NH 03755-3528