Choosing a Telescope

Choosing a telescope depends on what you plan to use it for.
Other factors include: cost, versatility, and portability.
Some amateur astronomers even build their own telescopes.

There are three basic types of telescopes:
Refractors
Reflectors
Catadioptrics

A refractor is basically a long tube that allows light to pass through, in a straight fashion, from the front objective lens to the eyepiece, at the other end of the tube. Its what most folks identify with, when telescope comes to mind. They are also pretty easy to use and work well for lunar, planetary and binary star observation.

A reflector uses a concave mirror to gather and focus light onto a flat mirror, that reflects the image out of an opening at the side of the tube, through the eyepiece. This is a bit more complex than the above telescope, but great for viewing remote galaxies, nebulae and star clusters.

A catadioptric utilizes a combination of mirrors and lenses to complexly fold the optics and form an image. There are two popular designs: The Schmidt-Cassegrain and the Maksutov-Cassegrain. The later is thought to be "not as good" as the Schmidt-Cassegrain, due to its thick correcting lens. The catadioptric telescope can be rather expensive, but you get exceptionally sharp images, and its super for all kinds of observation and photography.
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