The Argunov Cassegrain telescope is a
telescopedesign first introduced in 1972 by P.P. Argunov. All optics are spherical, and the classical Cassegrain secondary mirror is replaced by three air-spaced lens elements. The element farthest from the primary mirror is a Mangin mirror, which acts as a second surface mirror, having a reflective coating applied to the surface facing the sky. Argunov systems only employ spherical surfaces and avoid the practical difficulties of making and testing aspheres. However, this seeming 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 asphere of equivalent precision.
*P.P. Argunov, "Isochromatic telescope designs with spherical optics." Astron. Vestn. 6 (1), 52 (1972)
Wikimedia Foundation. 2010.
Look at other dictionaries:
Cassegrain reflector — The Cassegrain reflector is a combination of two coaxial reflectors used in Cassegrain telescopes and radio antennas.First developed in 1672 by Laurent Cassegrain, this reflector is a combination of a primary concave mirror and a secondary convex … Wikipedia
List of telescope types — There are three main types of optical telescopes and these are divided into subgroups. They all have their different advantages and disadvantages and they are used in different areas of astronomy.Refractors (Dioptrics) * Non achromatic *… … Wikipedia
Catadioptric system — A 150 mm aperture catadioptric telescope (Maksutov) A catadioptric optical system is one where refraction and reflection are combined in an optical system, usually via lenses (dioptrics) and curved mirrors (catoptrics). Catadioptric… … Wikipedia
Meniscus corrector — Albert Bouwers 1941 catadioptric telescope with a concentric meniscus corrector A meniscus corrector is a negative meniscus lens that is used to correct spherical aberration in image forming optical systems such as catadioptric telescopes. They… … Wikipedia
Scientific phenomena named after people — This is a list of scientific phenomena and concepts named after people (eponymous phenomena). For other lists of eponyms, see eponym. NOTOC A* Abderhalden ninhydrin reaction Emil Abderhalden * Abney effect, Abney s law of additivity William de… … Wikipedia
Korrektor (Teleskop) — Ein Korrektor ist eine spezielle Anordnung von Linsen oder Spiegeln, die Abbildungsfehler eines Fernrohrobjektivs vermindert oder Abbildungsfehler durch die atmosphärische Dispersion (chromatische Aberration) beseitigt. Es gibt verschiedene… … Deutsch Wikipedia
Mangin mirror — Diagram of a Mangin mirror. In optics, a Mangin mirror is a negative meniscus lens with the reflective surface on the rear side of the glass forming a curved mirror that reflects light without spherical aberration. This reflector was invented in… … Wikipedia