Basically, there are three types of telescopes that are available for amateur astrologers to purchase:
- Refractors that use a lens that is the primary device for gathering light.
- Reflectors that use a mirror that is the primary device for gathering light.
- Compound telescopes that use a combination of lenses and mirrors to gather light.
The type that one needs is based upon at least three factors:
- The type of observations the user wants to make
- The area in which the user will use the telescope
- The financial resources of the user
First, let's talk about the location where you will be using your telescope.
1. If you will be using your telescope in a well-lighted urban area, you should probably go with a compound telescope, because they tend to do better than either refractors or reflectors in urban conditions.
2. If you will be using your telescope in the suburbs that are not as well lit as a densely populated urban area, you can choose the type telescope you want based entirely upon the type of observations you intend to make, because all types work equally well.
3. If you will be using your telescope in a very rural setting, you should consider compound telescopes and reflectors because they do seem to work better in very low-light situations.
The power of the telescope that you buy will depend upon what you want to observe. A small 2-4" ACH or APO refractor will work well for observing the moon and the planets, but not for observing the deep sky.
A > 6" compound will work the best for general use, but a 6"-25" reflector will work best for deep sky and faint deep sky observations.