TelescopeChoice.com

First things first – stay away from department stores and ebay (unless you really know what you’re doing)! Department stores sell awful telescopes which are likely to destroy your interest in astronomy. They are often made with plastic lenses and boast of massive magnification which in itself is as ridiculous as it is pointless! Magnification is not the point – light gathering is.

To gather light we need the biggest aperture we can afford and use practically. The diameter of our lens or mirror is the biggest factor in the scheme of things. A good general rule is the one which says the highest possible magnification is limited to twice the aperture in millimeters, so a 70mm refractor has a maximum magnification ability of 140x. No matter what the box says.

That now said, it must be remembered that we need to be talking about decent optical quality as a small telescope with good optics will outperform a large scope with poor optics.

The ‘quality’ of the viewing location is also worth thinking about as there is a huge difference between the results you can achieve between a rural dark sky location and a light polluted suburban one. The darker the observing site the better off you will be and even a small telescope will give good results in a great location.

Now lets think about ease of set-up and use. The most practical telescopes are the ones which get used most. In other words don’t rush off to spend a fortune on a large telescope if its size means you rarely use it. Bear in mind also that if you are in a light polluted area the bigger the scope the larger the amount of light pollution you are also suffering.

Confused enough? Now add in to the equation that the mount your telescope sits on is just as important as the telescope itself. A cheap and nasty mount will cause shake and vibration in the telescope which will absolutely destroy your chances of getting a reasonable view.

Quick Tip – To get the biggest aperture on a steady mount with very simple operation, get yourself a Dobsonian telescope, they’re large aperture and simple to operate.

Now you’re probably wondering whether to buy a scope with all the fancy tracking and automatic targetting. By all means if you can afford it do so but understand you do not actually need it and it will tend to make you a little lazy when it comes to learning to find your own way around the skies.

Now all of the above being said, repeat after me – the best telescope for you is the one you are going to use the most! It is completely pointless you having a great big computerized whizz bang catadioptric if its sheer size, weight and complexity means you rarely set it up. So think about how and when you are likely to use your telescope and get the one that is going to be most practical for you.

Bear in mind that many amateur astronomers have two or more telescopes for different uses. A small refractor for casual quick and easy backyard use and something bigger for when they get the opportunity to go to a dark sky location or maybe even do some astrophotography.

Newtonian Reflector type scopes tend to be most popular with beginners as they offer fairly large apertures for the outlay and are simple to set up and operate. They require a little maintenance and collimation (the process of ensuring the mirror is correctly aligned) and are not a great choice if you live in a dusty outback area as the open tube tends to gather dust on the mirrors.

Refractors are great at resolving detail and tend to ‘punch’ through light pollution better than reflectors however can be very expensive for the larger aperture ones. Short tube refractors are more affordable now and their small size makes them highly portable. The short tubes result in wide angle views so they’re great for learning your way around the heavens. Refractors tend to be pretty much maintenance free due to the closed tube design

Catadioptrics such as the Shmidt-Cassegrain and Maksutov-Cassegrain telescopes tend to be most popular with more experienced observers and astro-photographers. They are really a bit of a combination of reflector and refractor and again require a little maintenance. They offer superb viewing and photography.

Dobsonian Telescopes are really large reflectors mounted on a simple turntable, their simplicity makes them cheapest in the aperture for dollar stakes. The huge apertures mean they can offer excellent light gathering and therefore very high magnifications, if thats what you’re after.

Your new telescope should come with an eyepiece or two to get you started. The eyepiece is actually the part that gives us our magnification. To calculate the magnification factor you are getting out of the combination of your telescope and the eyepiece just divide the focal length of the scope by the focal length of the eyepiece e.g. a scope  with a focal length of 1000mm in combination with a 10mm eyepiece gives a magnification factor of 100.

So what can you see with these telescopes assuming good viewing conditions? This is by no means an exhaustive list, just a broad idea of what you might be able to see.

At the small refractor end of the scale, excellent lunar views, cloud belts on Jupiter, a ring around Saturn and the larger globular star clusters. Astronomers use an increasing measure of magnitude the fainter the star, these small scopes can allow you to see stars down to magnitude 11 or so.

By the time you get to the 6inch reflectors you can distinguish the polar ice caps on Mars, detail in Jupiter’s cloud belts, certainly its moons, the Cassini division in Saturns rings  and Saturn’s moons along with many nebulas and galaxies.

With the big catadioptrics you can even see far flung Pluto though only as a pinprick of light and thousands of nebulas and galaxies in good detail. See faint stars down to magnitude 14 or 15.