Although telescopes are the first thought for sky gazers, binoculars may be the ideal choice. Being portable, they are more convenient and inexpenseve compared with telescopes. It's wiser to buy a cheap pair of binoculars instead of a cheap telescope. 7 X 35 binoculars are a good choice because the size is light and easy to hold. The number 7 stands for the magnification produced by the binocular eyepiece, and the other number stands for the aperature in millimeters.

There are three types of telescopes available for beginning astronomers.

Refractors are the most readily recognized type and consist of lenses at both ends of a tube. Whatever you do avoid the cheap models sold by department, nature/science and toy stores. They quote large magnifications, but their small apertures make them useless for astronomy. Remember a telescope's most important job is to collect light, not magnify a image. A normal terrestrial telescope has an extra lens to ensure the image is the right way up. However extra lenses cut down the amount of light reaching the eye. The one thing an astronomer wants to avoid is reducing light and therefore information. So the correcting lens is omitted and a true astronomical telescope gives an upside down (inverted) image. Lenses can create false rainbow tints around very bright objects like planets. This is called chromatic aberration and can be ignored or corrected by a filter. Refractors generally cost more per inch of aperture than other types of telescope, and those of more than 4-inch (100mm) aperture are rather long and cumbersome. However smaller good quality ones can make excellent beginner instruments.

The next type of telescope is called the reflector, and these are usually comfortable because of the eyepiece position. In this telescope, light reflects off mirrors as is travels down the telescope tube and through the eyepiece on the side. In order to be as useful as a refractor, the reflector must be larger in size. Although they don't create false rainbow images, the main mirror on a reflector often needs to be readjusted, and there are kits for this. A popular type of reflector is called a Dobsonian, and this is convenient because it has a mount instead of a tripod.

The final type of amateur telescope is the Schmidt-Cassegrain, and this uses lenses and mirrors to fold a light path back onto itself within a compacted tube. This telescope is usually less expensive than refractors, dearer than reflectors, and are easier to handle than both.

Sometimes telescope specifications quote numbers which will not affect the image you see. However, they can affect the exposure you need if you start into astrophotography. It is wise to get familiar with your telescope and the sky before you look into astrophotography though.

You may be able to evaluate the different instruments by joining a local astronomy club or attending one of their star parties. Check at your local library. You can also look in a reputable astronomy magazine for reviews and manufacturers advertising good quality telescopes.

Even though you should purchase the largest aperture you find, keep in mind you may not want a large telescope as you may have to carry it around. Smaller telescopes are easier to set up and use, and high pollution in your area can keep a large telescope from producing results to its full potential.

The best way to calculate the maximum practical magnification is to double the aperture number: i.e. a 60mm aperture shoudl yield a 120x magnification. You shouldn't waste time on buying telescope accessories, but should instead invest in the largest aperture you can find. However, don't be tempted to purchase an eyepiece that claims to stretch magnification beyond the calculated aperture value. Start off simple in terms of eyepieces. A Kellner eyepiece is a great general purpose piece, and if you place a Barlow lens between it and a focuser, magnification may be tripled.

In order to keep a moving object in view, a telescope may have to be moved repeatedly. To help with this, mounts and drives have been created. Electronic drives will help point the telescope, and it's important to have a sturdy mount.

It may be saddening to know that many textbook photos have false colors and are long exposures. The eye is not sensitive enough to see color in dim objects, and stars will always look like tiny light points.

So what can you expect to see with a beginners telescope? A 3-inch (75mm) refractor or 6-inch (150mm) reflector will allow you to see many galaxies and nebulae, Saturn's rings, Jupiter's largest moons and hundreds of craters on the moon. Plenty of wonderful objects to serve as an introduction to the night sky.

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David Wildash posts information and tips on his website about Telescopes , and you can read more about buying a telescope