Maksutov–Cassegrain
250px, A 150mm aperture Maksutov–Cassegrain telescope The Maksutov (also called a "Mak") is a catadioptric telescope design that combines a spherical mirror with a weakly negative meniscus lens in a design that takes advantage of all the surfaces being nearly "spherically symmetrical". The negative lens is usually full diameter and placed at the entrance pupil of the telescope (commonly called a "corrector plate" or "meniscus corrector shell"). The design corrects the problems of off-axis aberrations such as coma found in reflecting telescopes while also correcting chromatic aberration. It was patented in 1941 by Soviet optician Dmitri Dmitrievich Maksutov. Maksutov based his design on the idea behind the Schmidt camera of using the spherical errors of a negative lens to correct the opposite errors in a spherical primary mirror. The design is most commonly seen in a Cassegrain variation, with an integrated secondary, that can use all-spherical elements, thereby simplifying f ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |
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Amateur Telescope Making
Amateur telescope making is the activity of building telescopes as a hobby, as opposed to being a paid professional. Amateur telescope makers (sometimes called ATMs) build their instruments for personal enjoyment of a technical challenge, as a way to obtain an inexpensive or personally customized telescope, or as a research tool in the field of astronomy. Amateur telescope makers are usually a sub-group in the field of amateur astronomy. Beginnings Ever since Galileo Galilei adapted a Dutch invention for astronomical use, astronomical telescope making has been an evolving discipline. Many astronomers after the time of Galileo built their own telescopes out of necessity, but the advent of amateurs in the field building telescopes for their own enjoyment and education seems to have come into prominence in the 20th century. Before the advent of modern mass-produced telescopes, the price of even a modest instrument was often beyond the means of an aspiring amateur astronomer. Buildin ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |
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Maksutov 150mm
Maksutov may refer to: * Maksutov telescope, a catadioptric telescope with a meniscus corrector . * Dmitry Dmitrievich Maksutov (1896–1964), Russian optical engineer, inventor of the Maksutov telescope * Maksutov (crater), a lunar crater named after Dmitry Dmitrievich Maksutov * 2568 Maksutov, a main-belt asteroid named after Dmitry Dmitrievich Maksutov See also * Maksutov (surname) {{disambiguation ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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John F
John is a common English name and surname: * John (given name) * John (surname) John may also refer to: New Testament Works * Gospel of John, a title often shortened to John * First Epistle of John, often shortened to 1 John * Second Epistle of John, often shortened to 2 John * Third Epistle of John, often shortened to 3 John People * John the Baptist (died ), regarded as a prophet and the forerunner of Jesus Christ * John the Apostle (died ), one of the twelve apostles of Jesus Christ * John the Evangelist, assigned author of the Fourth Gospel, once identified with the Apostle * John of Patmos, also known as John the Divine or John the Revelator, the author of the Book of Revelation, once identified with the Apostle * John the Presbyter, a figure either identified with or distinguished from the Apostle, the Evangelist and John of Patmos Other people with the given name Religious figures * John, father of Andrew the Apostle and Saint Peter * Pope Jo ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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PerkinElmer
PerkinElmer, Inc., previously styled Perkin-Elmer, is an American global corporation that was founded in 1937 and originally focused on precision optics. Over the years it went into and out of several different businesses via acquisitions and divestitures; these included defense products, semiconductors, computer systems, and others. By the 21st century, PerkinElmer was focused in the business areas of diagnostics, life science research, food, environmental and industrial testing. Its capabilities include detection, imaging, informatics, and service. It produced analytical instruments, genetic testing and diagnostic tools, medical imaging components, software, instruments, and consumables for multiple end markets. PerkinElmer was part of the S&P 500 Index and operated in 190 countries. Over its history, PerkinElmer has been split in two twice. In 1999, PerkinElmer merged with EG&G, with the ongoing Analytical Instruments Division of Perkin-Elmer keeping that name, while the life ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Questar Corporation
Questar Corporation is a company based in New Hope, Pennsylvania. It manufactures precision optical devices for consumer, industrial, aerospace, and military markets. Its telescopes produced for the consumer market are sold under the brand name "Questar". History Questar was founded in 1950 by Lawrence Braymer, who set up Questar to develop and market Maksutov telescopes and other optical devices for the consumer, industrial, and government customers. The Questar Standard telescope has been in production since 1954. Questars have been associated with many well-known scientists and other personalities; for example, in 1959, Wernher von Braun purchased a telescope manufactured by the company. Products Questar produces telescopes for consumer, military, police, security, aerospace, and industrial applications. Products sold by Questar include 3.5” (89 mm) and 7” (178 mm) aperture Maksutov Cassegrain astronomical/terrestrial telescopes for the consumer market. For a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Maksutov Spot Cassegrain
Maksutov may refer to: * Maksutov telescope 250px, A 150mm aperture Maksutov–Cassegrain telescope The Maksutov (also called a "Mak") is a catadioptric telescope design that combines a spherical mirror with a weakly negative meniscus lens in a design that takes advantage of all the sur ..., a catadioptric telescope with a meniscus corrector . * Dmitry Dmitrievich Maksutov (1896–1964), Russian optical engineer, inventor of the Maksutov telescope * Maksutov (crater), a lunar crater named after Dmitry Dmitrievich Maksutov * 2568 Maksutov, a main-belt asteroid named after Dmitry Dmitrievich Maksutov See also * Maksutov (surname) {{disambiguation ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Secondary Mirror
A secondary mirror (or secondary) is the second deflecting or focusing mirror element in a reflecting telescope. Light gathered by the primary mirror is directed towards a focal point typically past the location of the secondary. Secondary mirrors in the form of an optically flat ''diagonal mirror'' are used to re-direct the light path in designs such as Newtonian reflectors. They are also used to re-direct and extend the light path and modify the final image in designs such as Cassegrain reflectors. The secondary is typically suspended by X-shaped struts (sometimes called a "spider") in the path of light between the source and the primary, but can be mounted on other types of mounts or optical elements such as optical windows, or schmidt and meniscus corrector plates. Employing secondary mirrors in optical systems causes some image distortion due to the obstruction of the secondary itself, and distortion from the spider mounts, commonly seen as cross-shaped diffraction spike ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Newtonian Telescope
The Newtonian telescope, also called the Newtonian reflector or just a Newtonian, is a type of reflecting telescope invented by the English scientist Sir Isaac Newton, using a concave primary mirror and a flat diagonal secondary mirror. Newton's first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope. The Newtonian telescope's simple design has made it very popular with amateur telescope makers. Description [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Journal Of The Optical Society Of America
The ''Journal of the Optical Society of America'' is a peer-reviewed scientific journal of optics, published by Optica. It was established in 1917 and in 1984 was split into two parts, A and B. ''Journal of the Optical Society of America A'' Part A covers various topics in optics, vision, and image science. The editor-in-chief is Olga Korotkova (University of Miami, USA). ''Journal of the Optical Society of America B'' Part B covers various topics in the field of optical physics, such as guided waves, laser spectroscopy, nonlinear optics, quantum optics, laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word ''laser'' originated as an acronym for light amplification by stimulated emission of radi ...s, organic and polymer materials for optics, and ultrafast phenomena. The editor-in-chief is Kurt Busch ( Humboldt University of Berlin, Germany). References ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |