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Meniscus Corrector Shell
A meniscus corrector is a negative meniscus lens that is used to correct spherical aberration in image-forming optical systems such as catadioptric telescopes. It works by having the equal but opposite spherical aberration of the objective it is designed to correct (usually a spherical mirror). Types Meniscus correctors are used as full aperture correctors, most commonly in a Maksutov telescope sub type called the Gregory or “spot” Maksutov–Cassegrain telescope. They are also used in the Bouwers meniscus telescope. There are Maksutov variations that use the same principle but place the meniscus lens as a sub-aperture corrector near the focus of the objective. There are other sub-aperture meniscus corrector catadioptric telescopes such as the Argunov–Cassegrain telescope and the Klevtsov–Cassegrain telescope. Invention The idea of using the spherical aberration of a meniscus lens to correct the opposite aberration in a spherical objective dates back as far as W. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bouwers Meniscus Telescope Concentric
Bouwer or Bouwers is a surname. Notable people with the surname include: * Alba Bouwer (1920-2010), South African Afrikaans-writing journalist and author * Albert Bouwers (1893–1972), Dutch optical engineer * Ben Bouwer (Barend Daniël Bouwer, 1875-1938), Boer War general, police officer and colonel in South Africa * Marc Bouwer, South African-born American fashion designer {{surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig Schupmann
Ludwig Ignaz Schupmann (23 January 1851 in Geseke (Westphalia), Kingdom of Prussia – 2 October 1920 also in Geseke) was a German professor of architecture Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and construction, constructi ... and an optical designer. He is principally remembered today for his Medial and Brachymedial telescopes, types of Catadioptric system, catadioptric reflecting-refracting telescopes with Mangin mirrors that eliminate chromatic aberrations while using common optical glasses. Used in early lunar studies, they are used now in double-star work. Schupmann candelabra (a special street light) In 1882, electric street lighting was put into operation in the center of the city of Berlin (Potsdamer Platz and Leipziger Straße) for which the company Siemens & Halske supplied a total of 36 c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catadioptric System
A catadioptric optical system is one where refraction and Reflection (physics), reflection are combined in an optical system, usually via lens (optics), lenses (dioptrics) and curved mirrors (catoptrics). Catadioptric combinations are used in focusing systems such as searchlights, headlamps, early lighthouse focusing systems, optical telescopes, microscopes, and telephoto photographic lens, lenses. Other optical systems that use lenses and mirrors are also referred to as "catadioptric", such as surveillance catadioptric sensors. Early catadioptric systems Catadioptric combinations have been used for many early optical systems. In the 1820s, Augustin-Jean Fresnel developed several catadioptric lighthouse reflector versions of his Fresnel lens. Léon Foucault developed a catadioptric microscope in 1859 to counteract aberrations of using a lens to image objects at high power. In 1876 a French engineer, A. Mangin, invented what has come to be called the Mangin mirror, a concave glas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatic Aberration
In optics, chromatic aberration (CA), also called chromatic distortion, color aberration, color fringing, or purple fringing, is a failure of a lens to focus all colors to the same point. It is caused by dispersion: the refractive index of the lens elements varies with the wavelength of light. The refractive index of most transparent materials decreases with increasing wavelength. Since the focal length of a lens depends on the refractive index, this variation in refractive index affects focusing. Since the focal length of the lens varies with the color of the light different colors of light are brought to focus at different distances from the lens or with different levels of magnification. Chromatic aberration manifests itself as "fringes" of color along boundaries that separate dark and bright parts of the image. Types There are two types of chromatic aberration: ''axial'' (''longitudinal''), and ''transverse'' (''lateral''). Axial aberration occurs when different wavelengt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astigmatism (optical Systems)
An optical system with astigmatism is one where rays that propagate in two perpendicular planes have different foci. If an optical system with astigmatism is used to form an image of a cross, the vertical and horizontal lines will be in sharp focus at two different distances. The term comes from the Greek α- (''a-'') meaning "without" and στίγμα (''stigma''), "a mark, spot, puncture". Forms of astigmatism There are two distinct forms of astigmatism. The first is a third-order aberration, which occurs for objects (or parts of objects) away from the optical axis. This form of aberration occurs even when the optical system is perfectly symmetrical. This is often referred to as a "monochromatic aberration", because it occurs even for light of a single wavelength. This terminology may be misleading, however, as the ''amount'' of aberration can vary strongly with wavelength in an optical system. The second form of astigmatism occurs when the optical system is not symmetri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coma (optics)
In optics (especially telescopes), the coma (), or comatic aberration, in an optical system refers to aberration inherent to certain optical designs or due to imperfection in the lens or other components that results in off-axis point sources such as stars appearing distorted, appearing to have a tail (coma) like a comet. Specifically, coma is defined as a variation in magnification over the entrance pupil. In refractive or diffractive optical systems, especially those imaging a wide spectral range, coma can be a function of wavelength, in which case it is also a form of chromatic aberration. Overview Coma is an inherent property of telescopes using parabolic mirrors. Unlike a spherical mirror, a bundle of parallel rays parallel to the optical axis will be perfectly focused to a point (the mirror is free of spherical aberration), no matter where they strike the mirror. However, this is only true if the rays are parallel to the axis of the parabola. When the incoming rays str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dennis Gabor
Dennis Gabor ( ; ; 5 June 1900 – 9 February 1979) was a Hungarian-British physicist who received the Nobel Prize in Physics in 1971 for his invention of holography. He obtained British citizenship in 1946 and spent most of his life in England. Life and career Gabor was born as Günszberg Dénes, into a Jewish family in Budapest, Austria-Hungary. In 1900, his family converted to Lutheranism. Dennis was the first-born son of Günszberg Bernát and Jakobovits Adél. Despite having a religious background, religion played a minor role in his later life and he considered himself agnostic. In 1902, the family received permission to change their surname from Günszberg to Gábor. He served with the Hungarian artillery in northern Italy during World War I. He began his studies in engineering at the Budapest University of Technology and Economics in 1918, later in Germany, at the ''Technische Hochschule Charlottenburg'' in Berlin, now known as Technische Universität Berlin. At ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dmitri Dmitrievich Maksutov
Dmitry Dmitrievich Maksutov (; – 12 August 1964) was a Soviet Union, Soviet Optical engineering, optical engineer and amateur astronomer. He is best known as the inventor of the Maksutov telescope. Biography Dmitry Dmitriyevich Maksutov was born in 1896 in either Nikolayev or the port city of Odesa, Russian Empire. His father, was a naval officer serving with the Black Sea Fleet, who came from a family with a long and distinguished naval tradition. His great-grandfather, Peter Ivanovich Maksutov, was given the title of prince, thereby raising the family to hereditary nobility as a reward for bravery in combat. His grandfather, Dmitri Petrovich Maksutov, was the last Russian governor of Russian Alaska, before it was purchased by the United States in 1867. Dmitri became interested in astronomy in early childhood, and constructed his first telescope (a 7.2 inch / 180 mm reflecting telescope, reflector) when he was twelve years old. Later he read publications by the Russ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Bouwers
Albert A. Bouwers (1893–1972) was a Dutch optical engineer.Ian Ridpath, "Bouwers telescope", ''A Dictionary of Astronomy'', 199first sentence of article/ref> He is known for developing and working with X-rays and various optical technologies as a high-level researcher at Philips research labs. He is lesser known for patenting in 1941 a catadioptric meniscus telescope design similar to but slightly predating the Maksutov telescope. Biography Bouwers was born in the town of Dalen in the Netherlands in 1893.Reflecting Telescope Optics, by Ray N. Wilson, page 498Google Books, pg 498/ref> He obtained his Ph.D. from Utrecht University in 1924, with a dissertation entitled in Dutch ''Over het meten der intensiteit van Röntgenstralen''. He was also the director of the Philips Laboratory's X-ray department. Bouwers developed a night vision device for viewing in low light conditions, called the "night eye". Albert Bouwers built a prototype for a design for a wide field concentric me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schmidt Corrector Plate
A Schmidt camera, also referred to as the Schmidt telescope, is a catadioptric astrophotographic telescope designed to provide wide fields of view with limited aberrations. The design was invented by Bernhard Schmidt in 1930. Some notable examples are the Samuel Oschin telescope (formerly Palomar Schmidt), the UK Schmidt Telescope and the ESO Schmidt; these provided the major source of all-sky photographic imaging from 1950 until 2000, when electronic detectors took over. A recent example is the Kepler space telescope exoplanet finder. Other related designs are the Wright camera and Lurie–Houghton telescope. Invention and design The Schmidt camera was invented by Estonian-German optician Bernhard Schmidt in 1930. Its optical components are an easy-to-make spherical primary mirror, and an aspherical correcting lens, known as a Schmidt corrector plate, located at the center of curvature of the primary mirror. The film or other detector is placed inside the camera, at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
