Telescope Types

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There are only two basic types of telescopes. These consist of:

1. Reflectors
2. Refractors

All telescopes, no matter how large, are variants of one of these types.

All telescopes larger than 40" are reflectors.

By the way, The largest refractor telescope is the 40" telescope made by Alvin Clark, mounted in 1897 at Yerkes Observatory.

The largest single mirror telescope in the world is no longer the 200" telescope on Mount Palomar. (200" is approx 5.4 meters)

It has been outdone by the 8.3 meter (approx 307") on top of Mauna Kea in Hawaii. The SUBARU Telescope of the National Observatory of Japan. The mirror thickness is only 20 cm That is Centimeters !

The largest multiple mirror telescope is the Keck telescope on Mauna Kea in Hawaii.

Their instruments are the twin Keck Telescopes, the world's largest optical and infrared telescopes. Each stands eight stories tall and weighs 300 tons, yet operates with nanometer precision. At the heart of each Keck Telescope is a revolutionary primary mirror. Ten meters in diameter, the mirror is composed of 36 hexagonal segments that work in concert as a single piece of reflective glass.

Image of Hale 200" telescope

Image of the 8.3 meter Subaru

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