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The Argunov–Cassegrain telescope is a catadioptric telescope design first introduced in 1972 by P. P. Argunov. All optics are spherical, and the classical
The Argunov–Cassegrain telescope is a catadioptric telescope design first introduced in 1972 by P. P. Argunov. All optics are spherical, and the classical Cassegrain Cassegrain may refer to
* Cassegrain reflector, a design used in telescopes
* Cassegrain antenna, a type of parabolic antenna
* Cassegrain (crater), on the Moon
* a Belgian canned vegetables producer now part of Bonduelle S.A.
People :
* Guillaume ...
secondary mirror is replaced by a sub-aperture secondary corrector group consisting of three air-spaced elements, two lenses
A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements ...
and a Mangin mirror (the element farthest from the primary mirror).
Discussion
Argunov systems only employ spherical surfaces and avoid the practical difficulties of making and testingasphere
An aspheric lens or asphere (often labeled ''ASPH'' on eye pieces) is a lens whose surface profiles are not portions of a sphere or cylinder. In photography, a lens assembly that includes an aspheric element is often called an aspherical lens.
T ...
s. However, this benefit is marginal, as it is almost as difficult to make a true zone-free sphere of precise radius of curvature as it is to make an aspheric surface with comparable precision. Further, since multiple surfaces are involved, creating a design with good aberration correction can become very complicated.
See also
* Klevtsov–Cassegrain telescope * List of telescope typesReferences
Further reading
* *External links
* * Telescope types {{observatory-stub