[meteorite-list] telescope

From: Benjamin P. Sun <bpsun2009_at_meteoritecentral.com>
Date: Mon, 9 Jan 2012 21:13:16 -0500
Message-ID: <CAE1PX86iaqPOcQM_zdFKy_+9njHSS7c0qcFOoPpT0k87rfcB8Q_at_mail.gmail.com>

On a limited budget, a small refractor is best for casual planetary
and lunar viewing.

Small reflectors are more suited for viewing deep space objects, such
as galaxies and nebulas.
Avoid reflectors under 100mm in aperture. Their large central
obstruction from the secondary mirror blocks out too much light. You'd
get a better, brighter, sharper image through a 60mm refractor than
through a 80mm reflector.

I started out in astronomy decades ago with a quality 60mm tabletop
spotting scope with a zoom eyepiece. I could easily see all 4 of
Jupiters' moons, the rings of Saturn, the orange disk of Mars, the
phases of Venus, 7 stars of Pleiades, and Orion's nebula with it.
Ignore all the magnification power hype. A useful magnification
guideline is 50-60x per inch of aperture. So 60mm(2.4 inches) will
yield a maximum useful magnification of about 140x. More than enough
for the casual astronomer. Beyond that magnification and everything
begins to look crappy, dark and fuzzy.

Remember, even on a low budget, you can still find a good quality
scope. Look for a coated(multi-coated if you're lucky) air-spaced
achromatic lens and good multi-element .965" or 1.25" sized eyepieces.
A finderscope is a non-essential accessory and usually useless junk
anyways.
Received on Mon 09 Jan 2012 09:13:16 PM PST