Telescopes

In astronomy, we distinguish mainly 3 types of telescopes, though, types extend far beyond. Essentially, all telescopes work with the same principles. The three (main) types of telescopes are:

• refractor telescope
• reflector telescope
• catadioptric telescope

All telescopes have two very important values. These are:

1. diameter of telescope (first number)
2. focal length of telescope (second number)

which are all given in milimeters (mm).

So the format looks like this: 150/1400. In this case, the numbering means that the specific telescope has a diameter of 150 milimeters, and a focal length of 1400 milimeters.