Choosing the right telescope involves juggling the five "P"s of Performance, Purpose, Portability, Light Pollution, and Price. It's a juggling act that the information in the next few sections can make easier.
There are two kinds of observing and photography you can do with a telescope:
- Terrestrial (nature studies, bird watching, people-watching, etc.) and
- Astronomical (lunar, solar, planetary, and deep space).
And there are three general kinds of telescopes to do the observing:
- Refractors (variations on the all-lens type that Galileo first used in 1609);
- Reflectors (variations on the all-mirrors type that Newton first used in 1671); and
- Catadioptrics (20th century lens and mirror combinations in Schmidt-Cassegrain and Maksutov-Cassegrain optical designs, among others).
Most telescopes are capable, with varying degrees of success, of showing you and photographing thousands of the most intriguing sights in the skies and on the ground. But no telescope does it all perfectly. Every telescope and telescope type has a few observing areas where it really excels, and others where it's only adequate.
Refractors, for example, are usually better at high power observing of bright objects, like the Moon and planets, than they are at finding faint nebulas and galaxies. Large aperture reflectors are normally just the reverse - letting you see large and faint nebulas and galaxies outside the solar system that are simply too dim to be seen by a smaller refractor. So, which type of scope is better for you quite often depends on what kind of celestial objects interest you the most.
The first step in choosing a telescope, then, is to think about what in the skies you want to look at or photograph the most. If there are celestial sights that you just have to see with your own eyes, you can pick the kind of scope that excels at that kind of observing and imaging, while still knowing it will do a reasonable job of showing you the rest of the heavens. But, if you want to see it all, there are scopes that will do that, too.