|
Gauss Lens
The Gauss lens is a compound achromatic lens that uses two uncemented elements; in its most basic form, a positive meniscus lens on the object side and a negative meniscus lens on the image side. It was first proposed in 1817 by the mathematician Carl Friedrich Gauss for a refracting telescope design, but was seldom implemented and is better known as the basis for the Double-Gauss lens first proposed in 1888 by Alvan Graham Clark, which is a four-element, four-group compound lens that uses a symmetric pair of Gauss lenses. Design The power of the positive element predominates, but the negative element corrects for chromatic aberration; the positive element facing the object is made of crown glass, while the negative element facing the image is made of flint glass, separated by an air gap that takes the shape of a negative element. Gauss first described the arrangement in 1817. Alvan Clark & Sons built a telescope for Princeton University Princeton University is a private un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Friedrich Gauss
Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes referred to as the ''Princeps mathematicorum'' () and "the greatest mathematician since antiquity", Gauss had an exceptional influence in many fields of mathematics and science, and he is ranked among history's most influential mathematicians. Also available at Retrieved 23 February 2014. Comprehensive biographical article. Biography Early years Johann Carl Friedrich Gauss was born on 30 April 1777 in Brunswick (Braunschweig), in the Duchy of Brunswick-Wolfenbüttel (now part of Lower Saxony, Germany), to poor, working-class parents. His mother was illiterate and never recorded the date of his birth, remembering only that he had been born on a Wednesday, eight days before the Feast of the Ascension (which occurs 39 days after Easter). Ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flint Glass
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high Dispersion (optics), dispersion). Flint glasses are arbitrarily defined as having an Abbe number of 50 to 55 or less. The currently known flint glasses have refractive indices ranging between 1.45 and 2.00. A Lens (optics)#Types of simple lenses, concave lens of flint glass is commonly combined with a Lens (optics)#Types of simple lenses, convex lens of Crown glass (optics), crown glass to produce an achromatic doublet lens because of their compensating optical properties, which reduces chromatic aberration (colour defects). With respect to glass, the term ''flint'' derives from the flint nodules found in the chalk deposits of southeast England that were used as a source of high purity silica by George Ravenscroft, c. 1662, to produce a potash lead glass that was the precursor to English lead crystal. Traditionally, flint glasses were lead glasses containing around 4–60% lead(II) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeiss Planar
The Zeiss Planar is a photographic lens designed by Paul Rudolph at Carl Zeiss in 1896. Rudolph's original was a six-element symmetrical design. While very sharp, early versions of the lens suffered from flare due to its many air-to-glass surfaces. Before the introduction of lens coating technology, the four-element Tessar, with slightly inferior image quality, was preferred due to its better contrast. In the 1950s, when effective anti-reflective lens coatings became available, coated Planars were produced with much-improved flare resistance. These lenses used the Zeiss T coating system, which had been invented by Olexander Smakula in 1935. They performed very well as normal and medium-long focus lenses for small and medium format cameras. One of the most notable Planar lenses is the high-speed 2.0/110 mm lens for the 2000- and 200-series medium format Hasselblad cameras. See also * Carl Zeiss Planar 50mm f/0.7 * *Tessar * Sonnar *Biogon * * *Hologon *Photographic l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Zeiss AG
Carl Zeiss AG (), branded as ZEISS, is a German manufacturer of optical systems and optoelectronics, founded in Jena, Germany in 1846 by optician Carl Zeiss. Together with Ernst Abbe (joined 1866) and Otto Schott (joined 1884) he laid the foundation for today's multi-national company. The current company emerged from a reunification of Carl Zeiss companies in East and West Germany with a consolidation phase in the 1990s. ZEISS is active in four business segments with approximately equal revenue (Industrial Quality and Research, Medical Technology, Consumer Markets and Semiconductor Manufacturing Technology) in almost 50 countries, has 30 production sites and around 25 development sites worldwide. Carl Zeiss AG is the holding of all subsidiaries within Zeiss Group, of which Carl Zeiss Meditec AG is the only one that is traded at the stock market. Carl Zeiss AG is owned by the foundation Carl-Zeiss-Stiftung. The Zeiss Group has its headquarters in southern Germany, in the smal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Rudolph (physicist)
Paul Rudolph (14 November 1858 – 8 March 1935) was a German physicist who designed the first anastigmatic lens while working for Carl Zeiss. After World War I, he joined the Hugo Meyer optical company, where he designed most of their cine lenses. Work * 1890: First anastigmat lens "protar" * 1895: Planar design * 1899: Unar design * 1902: Tessar The Tessar is a photographic lens design conceived by the German physicist Paul Rudolph in 1902 while he worked at the Zeiss optical company and patented by Zeiss in Germany; the lens type is usually known as the Zeiss Tessar. A Tessar com ... design * 1918: Plasmat design * 1922: Kino-Plasmat design * 1926: Makro-Plasmat design * 1931: Kleinbild-Plasmat design References {{DEFAULTSORT:Rudolph, Paul 1858 births 1935 deaths 19th-century German inventors 19th-century German physicists Optical physicists Optical engineers 20th-century German inventors 20th-century German physicists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Museum Of American History
The National Museum of American History: Kenneth E. Behring Center collects, preserves, and displays the heritage of the United States in the areas of social, political, cultural, scientific, and military history. Among the items on display is the original Star-Spangled Banner (flag), Star-Spangled Banner. The museum is part of the Smithsonian Institution and located on the National Mall at 14th Street (Washington, D.C.), 14th Street and Constitution Avenue NW in Washington, D.C. History The museum opened in 1964 as the Museum of History and Technology. It was one of the last structures designed by the renowned architectural firm McKim Mead & White. In 1980, the museum was renamed the National Museum of American History to represent its mission of the collection, care, study, and interpretation of objects that reflect the experience of the American people. The museum site had previously held two Temporary buildings of the National Mall, temporary war buildings constructed in 194 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spherical Aberration
In optics, spherical aberration (SA) is a type of optical aberration, aberration found in optical systems that have elements with spherical surfaces. Lens (optics), Lenses and curved mirrors are prime examples, because this shape is easier to manufacture. Light rays that strike a spherical surface off-centre are refraction, refracted or reflection (physics), reflected more or less than those that strike close to the centre. This deviation reduces the quality of images produced by optical systems. Overview A spherical lens has an Optical aberration#Aberration of elements, i.e. smallest objects at right angles to the axis, aplanatic point (i.e., no spherical aberration) only at a radius that equals the radius of the sphere divided by the index of refraction of the lens material. A typical value of refractive index for crown glass is 1.5 (see List of refractive indices, list), which indicates that only about 43% of the area (67% of diameter) of a spherical lens is useful. It is o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Princeton University
Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest institution of higher education in the United States and one of the nine colonial colleges chartered before the American Revolution. It is one of the highest-ranked universities in the world. The institution moved to Newark, New Jersey, Newark in 1747, and then to the current site nine years later. It officially became a university in 1896 and was subsequently renamed Princeton University. It is a member of the Ivy League. The university is governed by the Trustees of Princeton University and has an endowment of $37.7 billion, the largest List of colleges and universities in the United States by endowment, endowment per student in the United States. Princeton provides undergraduate education, undergraduate and graduate education, graduate in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alvan Clark & Sons
Alvan Clark & Sons was an American maker of optics that became famous for crafting lenses for some of the largest refracting telescopes of the 19th and early 20th centuries. Founded in 1846 in Cambridgeport, Massachusetts, by Alvan Clark (1804–1887, a descendant of Cape Cod whalers who started as a portrait painter), and his sons George Bassett Clark (1827–1891) and Alvan Graham Clark (1832–1897). Five times, the firm built the largest refracting telescopes in the world. The Clark firm gained "worldwide fame and distribution", wrote one author on astronomy in 1899. The Dearborn telescope (housed successively at the University of Chicago, Northwestern University and Adler Planetarium) was commissioned in 1856 by the University of Mississippi. The outbreak of the Civil War prevented them from ever taking ownership. As a result, it was being tested in Cambridgeport when Alvan Graham observed Sirius B in 1862. In 1873 they built the objective lens for the ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Glass (optics)
Crown glass is a type of optical glass used in lenses and other optical components. It has relatively low refractive index (≈1.52) and low dispersion (with Abbe numbers around 60). Crown glass is produced from alkali-lime silicates containing approximately 10% potassium oxide and is one of the earliest low dispersion glasses. As well as the specific material named ''crown glass'', there are other optical glasses with similar properties that are also called crown glasses. Generally, this is any glass with Abbe numbers in the range 50 to 85. For example, the borosilicate glass Schott BK7 (Schott designates it as 517642. The first three digits tell you its refractive index (1.517) and the last three tell you its Abbé number (64.2))The crown/flint distinction is so important to optical glass technology that many glass names, notably Schott glasses, incorporate it. A ''K'' in a Schott name indicates a crown glass (''Krone'' in German — Schott is a German company). The ''B'' in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compound Lens
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''), usually arranged along a common axis. Lenses are made from materials such as glass or plastic, and are ground and polished or molded to a desired shape. A lens can focus light to form an image, unlike a prism, which refracts light without focusing. Devices that similarly focus or disperse waves and radiation other than visible light are also called lenses, such as microwave lenses, electron lenses, acoustic lenses, or explosive lenses. Lenses are used in various imaging devices like telescopes, binoculars and cameras. They are also used as visual aids in glasses to correct defects of vision such as myopia and hypermetropia. History The word ''lens'' comes from '' lēns'', the Latin name of the lentil (a seed of a lentil plant) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatic Aberration
In optics, chromatic aberration (CA), also called chromatic distortion and spherochromatism, 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. 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 wavelengths of light are focused at different distances from the lens (focus ''shift''). Longitudinal aberration is typical at long focal lengths. Transverse aberration occurs when different wavelengths are focused at different positions i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Carl Zeiss AG")
.jpg "Click for more on -> Chromatic Aberration")