Telescope Guide

Telescope Buying Guide

An optical telescope is a telescope which is used to gather, and focus light, for directly viewing a magnified image, making a photograph, etc. The term is used especially for a monocular with static mounting for observing the sky. Handheld binoculars are common for other purposes.

Light is made up of photons, and professional telescopes concentrate the light onto electronic detectors which collect the photons. There are two primary types of optical telescope: reflectors (which use mirrors) and refractors (which use lenses). In addition there are compound telescopes such as the Maksutov telescope and the Schmidt-Cassegrain telescope.

Telescopes are broadly classified into two main types.

1. Optical telescopes
2. Radio telescopes

Optical telescopes are also divided into two types.

1. Galilean refracting telescopes
2. Newtonian reflecting telescopes

Galilean or refracting telescopes employ the refractive properties of light, and are constructed of lenses. These can be used for both terrestrial and astronomical viewing.

Newtonian or reflecting telescopes employ the reflective properties of light, and use mirrors and lenses. These are more useful for astronomical viewing.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Optical Telescope"