The most bewildering question for a budding amateur is
which telescope to buy. Really, your first question should be, “Do I need a telescope?” Often the answer is no. This blog is intended to be an
introduction to observational astronomy, so you don’t need a telescope to
follow it. For anyone who does want a 'scope,
here are my thoughts on this perennial question.
The best telescope is the one that you get out and
use. Rather than rehashing information about types of telescope, I’m going to talk about my own equipment. Shop around for your perfect instrument; visit a star party or observing event so you can look
down some ‘scopes and see how big they are in the flesh. Let's start by considering the most frequently recommended telescope.
Use a web forum like Stargazer’s Lounge, ask
“What is the best telescope for a beginner?” and the answer always comes out the same – the best instrument for the beginner, by
a mile, is an 8’’ Dobsonian. The Dobsonian mount is alt-azimuth –
basically it has two axes: left and right, up and down. Very simple to use,
they offer a large aperture at a low price. Aperture, if you’re not down with the
jargon, is the width of the hole and hence the optics, in this case a
mirror at the bottom of the tube. They cost under £300,
are large enough to access thousands of objects and show lots of detail. They are brilliant.
But there's a snag.
They weigh in at 23kg. My main
observing site is a park 500 yards from my flat. Even if I manage to wrestle
the damn thing outside, I’m not going to get it to the park on foot. Therefore
an 8’’ Dobsonian would be the wrong choice for me.
Here’s my ‘scope:
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| Lots of fun to be had at night in the park! This is on a spotter scope tripod borrowed from work - a nice option for a simple mounting, but you can't point it at the zenith (i.e. straight up). |
This is a Skywatcher Startravel 80, a wide-field refractor. Refractors are the classic telescope design, using lenses to collect and focus light. 3'' is small but at
around 6kg in weight I can actually get it to where I want to use it. So for me it’s
perfect. It has its cons: the aperture is small, so
I can’t find as much as I’d like, it suffers from false
colour and it’s a short focal length telescope – that means it’s great for large things,
but doesn't magnify much, so it’s less suited to looking at planets. Here's a low-quality snap of Saturn to give you an idea, taken using my wife's iPhone through the eyepiece:
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| n.b. when I was looking down the eyepiece we could see the rings and their shadow cast on the planet! |
Mine is
equatorially mounted, tilted so that it can track objects as they move across
the celestial globe. These mounts do take some getting used to; I learned to
handle one a long time ago and wouldn’t want it any other way, but it's not as intuitive as the Dobsonian.
What is a small ‘scope like this capable of?
- The Moon – plenty of detail to be seen, although not as fine as a larger scope
- Planets – not its forté; see the above photo
- Star clusters, nebulae and galaxies – Only the brightest are visible. Some objects require a dark sky too. You can forget seeing spiral arms of galaxies, but its brilliant on big star clusters, and the wide-field of view makes it easy to find stuff.
They cost roughly £130, so they won’t break the bank either.
If you’re looking for something for a child, then consider
one of the Tabletop Dobsonian designs, such as the Heritage 130P, a good choice
for portable astronomers too. The Dobsonian mounting is easy to use, at 6kg it's light enough to be handled independently and with 5’’ of aperture it'll show enough detail they won't get bored after five minutes.
I also use a pair of Nikon 10x40 binoculars. I’m not a fan of binoculars for
astronomy because I can't hold them still enough, but if you’re a casual observer and want
something ultra-portable, they’re great. They’re also brilliant for
learning the sky. In this blog I’ll talk a lot about the view through
binoculars, and even a small pair will show you plenty. For children under
eight, don’t bother with a telescope for now, get them binoculars instead. That way they can learn the sky and you can see whether its a lasting passion or a passing fad for them!
For further information, try one of the following links:
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