Eventually, there will come that time that you will finally purchase a telescope. But what type of telescope do you prefer?

There are three types to consider: A refracting telescope has a convex objective lens at one end and an eyepiece at the other.

A reflecting telescope does not use an objective lens, but rather a concave mirror. The mirror (called the "primary") sends light up through the tube where a small flat mirror (called the "secondary") intercepts it and sends it to the eyepiece on the side of the tube.

A catadioptric telescope is a special type of reflecting telescope that possesses a correcting lens at the top to form the image. Most catadioptics are of the Schmidt-Cassegrain design. The light passes through the corrector, it reflects off the primary and then off a curved secondary, finally passing through a hole in the main mirror and reaching the eyepiece.

Unfortunately, space is far too limited here to discuss all the possibilities of a purchase. What I will say here (again), is to keep it simple!

If you're just starting out, you might want to consider a 2.4 or 3-inch refractor or a 4 or 6-inch reflector. Make sure that the telescope can be quickly set up, yet has a sturdy mount. A good telescope is virtually useless if you mount it on a shaky or wobbly tripod.

Don't fall into the trap of purchasing what some amateurs refer to as a "trash telescope." For the amount of money you might spend for such an instrument, you would be better off investing in a pair of good binoculars.

Basically, a trash telescope is one that, along with having a poor mount, has been advertised by the manufacturer as promising "spectacular views" of the Moon or the rings of Saturn at magnifications of, say, 500-power or more. Unfortunately, too many uninitiated amateurs are "power happy." Any telescope will provide you with high magnification, but not only will you be increasing the size of the image, you'll also be increasing the effects of viewing an object through our turbulent atmosphere. A high-power image especially in a small telescope will often turn out quite dim and blurry.

A rule of thumb: The maximum amount of magnification for any telescope is 50 power per inch of aperture. So if you intend to buy a 6-inch reflector, 300-power is as high as you should ever attempt to go; the maximum for a 3-inch refractor should be 150 power. In fact, you'll probably be surprised to discover that your most pleasing views will come at much lower powers.

Sometimes, however, people get into trouble purchasing even a quality instrument.

These folks go right out a purchase a very expensive telescope, bring it home, try setting it up, and in the process get completely confused. One neighbor of mine did just this and ended up visiting me every other week with a "new problem," when it was simply a matter of properly adjusting the finderscope or collimating the mirror. She even queried me about the motor drive (which can be used to take long-exposure photographs): "I thought it would automatically point the telescope to what I wanted to see."