|
A
first telescope - There
are two types of telescope - reflectors, which use a mirror at the
bottom of the telescope to image, and refractors, which have a lens
at the top of the tube. It is the diameter of the mirror or lens
that determines the resolution - the bigger the diameter, the better
images you will see. Small
telescopes are generally not worth the cost - refractors below 3”
diameter and reflectors below 4” are generally not as good as the
binoculars described above. Also important is a sturdy tripod to
mount the telescope on, as the ones provided can sometimes be too
unsteady for a clear image. A stand with a pillar and feet is best
for the purpose.
Andrew
Conway from the Open University makes the following recommendations:
4"
to 5" reflector telescopes: many imported Russian ones are available
for under £300. Pros: They are cheap, sturdy and have good
optics (i.e. give very sharp images). Cons: They are heavy
and not very portable, difficult to upgrade, and rather basic.
Celestron
and Meade have a variety of 5" and below reflectors which are very
popular and have good optics and sturdy tripod stands. Pros:
Good optics, light compact and portable. Easily upgradeable and
have all kinds of add on gadgets. Cons: A bit more expensive,
and can sometimes be a little more fiddly to use because of their
compact size.
Reviews
of telescopes that have been available for the past few years, as
well as the very latest models and prices, can be found on the Test
Reports section of the Sky
and Telescope magazine website.
|