- Refractor
- Refracting telescopes use lenses to gather light.
(Lenses refract, or bend, the light.) Whether or not Galileo
actually developed the first refracting telescope, he was certainly
the first one to turn such a device on the stars.
The Yerkes 40-inch refractor is the largest refracting telescope in the
world.
- Reflector
- Reflecting telescopes use mirrors to gather light.
(Mirrors reflect the light.)
Reflectors were developed by Sir Isaac Newton in the 17th century.
The mirrors in these telescopes are curved and shallow.
Reflecting telesopes come in two types of designs:
- Newtonian:
- and Cassegrain:
