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Dialyte Lens
A dialyte lens (sometimes called a ''dialyt'') is a compound lens design that corrects optical aberrations where the lens elements are widely air-spaced. The design is used to save on the amount of glass used for specific elements or where elements can not be cemented because they have dissimilar curvatures. The word ''dialyte'' means "parted", "loose" or "separated" in Greek. Design In its simplest form, a ''dialyte'' can be formed by separating the elements in a cemented achromatic doublet of positive and negative lenses, although the powers of the individual elements must be increased to compensate. Applications Telescopes The idea of widely separating the color correcting elements of a lens dates back to W. F. Hamilton's 1814 catadioptric Hamiltonian telescope and Alexander Rogers' 1828 proposals for a ''dialytic refractor''. The goal was to combine a large crown glass objective with a much smaller flint glass downstream to make an achromatic lens since flint glass at that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lens (optics)
A lens is a transmissive optical device that 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, polished, or molded to the required 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 such as 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 , the Latin name of the lentil (a seed of a lentil pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Wall (inventor)
John Wall (26 June 1932 – 27 January 2018) was an English design engineer, amateur astronomer, amateur telescope maker and member of the British Astronomical Association. He lived in Coventry, England. Biography Wall's aptitude for engineering won him an apprenticeship with Vickers Armstrong at the age of sixteen in the town of Crayford where he was born. He served in the army with the Royal Electrical and Mechanical Engineers in early 1950s and there became interested in telescopes and astronomy. He went on to become a design engineer at Vickers and, while working there in 1969, came up with the idea for an accurate mechanically simple eyepiece mount for amateur telescopes, the Crayford focuser. He is also known for designing dialyte based refracting telescopes, coming up with the ''Zerochromat'' retrofocally corrected refractor, including a folded 30-inch f/12 version he built in 1999. This refracting telescope A refracting telescope (also called a refractor) is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optics
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of optical instruments, instruments that use or Photodetector, detect it. Optics usually describes the behaviour of visible light, visible, ultraviolet, and infrared light. Light is a type of electromagnetic radiation, and other forms of electromagnetic radiation such as X-rays, microwaves, and radio waves exhibit similar properties. Most optical phenomena can be accounted for by using the Classical electromagnetism, classical electromagnetic description of light, however complete electromagnetic descriptions of light are often difficult to apply in practice. Practical optics is usually done using simplified models. The most common of these, geometric optics, treats light as a collection of Ray (optics), rays that travel in straight lines and bend when they pass through or reflect from surfaces. Physical optics is a more comprehensive mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Lenses
Photography is the art, application, and practice of creating images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed in many fields of science, manufacturing (e.g., photolithography), and business, as well as its more direct uses for art, film and video production, recreational purposes, hobby, and mass communication. A person who operates a camera to capture or take photographs is called a photographer, while the captured image, also known as a photograph, is the result produced by the camera. Typically, a lens is used to focus the light reflected or emitted from objects into a real image on the light-sensitive surface inside a camera during a timed exposure. With an electronic image sensor, this produces an electrical charge at each pixel, which is electronically processed and stored in a digital image file for subsequent display or processing. The result w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Telescope Types
The following are lists of devices categorized as types of telescopes or devices associated with telescopes. They are broken into major classifications with many variations due to professional, amateur, and commercial sub-types. Telescopes can be classified by optical design or mechanical design/construction. Telescopes can also be classified by where they are placed, such as space telescopes. One major determining factor is type of light, or particle being observed including devices referred to as "telescopes" that do not form an image or use optics. Some telescopes are classified by the task they perform; for example Solar telescopes are all designs that look at the Sun, Dobsonian telescopes are designed to be low cost and portable, Aerial telescopes overcame the optical shortcomings of 17th-century objective lenses, etc. List of optical telescope types Optical telescopes can be classified by three primary optical designs (refractor, reflector, or catadioptric), by sub-designs of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooke Triplet
The ''Cooke triplet'' is a photographic lens designed and patented in 1893 by Dennis Taylor who was employed as chief engineer by T. Cooke & Sons of York. It was the first lens system that allowed the elimination of most of the optical distortion or aberration at the outer edge of the image. The ''Cooke triplet'' is noted for being able to correct the five Seidel aberrations. The compound lens design consists of three air-spaced simple lens elements: two biconvex (positive) lenses surrounding a biconcave (negative) lens in the middle. It is one of the most important objective designs in the history of photography. Design According to Taylor, the lens design was derived by considering a cemented achromatic doublet consisting of one thin negative element and one thin positive element, both of equal power; such a doublet would result in a compound lens with zero net power but also a flat field of focus. However, by separating the elements, the resulting air gap would act a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goerz (company)
C. P. Goerz was founded in 1886 by Carl Paul Goerz. Originally, it made geometrical drawing instruments for schools. From 1888 it made cameras and photographic lenses. During the World War I, First World War, Goerz's main production was for the German and Austrian military. Goerz is known primarily for Anschütz strut-folding cameras, Dagor and Tengor lenses, Tenax cameras (later continued by Zeiss Ikon) and Minicord subminiature cameras. C. P. Goerz also made a series of telescopic sights for sporting rifles that saw some use during the shortage of military sniping rifles experienced during the early stages of the trench warfare that was to characterise much of the First World War. In 1895 Goerz founded a branch in New York that was to become the C. P. Goerz American Optical Company in 1905. This company continued to operate independently in the USA until 1972. In 1908, Goerz Photochemisches Werk GmbH was founded in Zehlendorf, Berlin. This company produced roll film and film ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anastigmat
An anastigmat or anastigmatic lens is a photographic lens completely corrected for the three main optical aberrations: spherical aberration, coma (optics), coma, and Astigmatism (optical systems), astigmatism. Early lenses often included the word ''Anastigmat'' in their name to advertise this new feature (''Doppel-Anastigmat'', ''Voigtländer Anastigmat Skopar'', etc.). History Early designs The first ''Anastigmat'' was designed by Paul Rudolph (physicist), Paul Rudolph for the German firm Carl Zeiss AG in 1890 and marketed as the ''Protar''; it consisted of four elements in two groups, as an asymmetric arrangement of two cemented achromatic lens doublets and was improved to a five-element, two-group design in 1891, substituting a cemented triplet for the rear group. In 1892, the Swiss mathematician Emil von Höegh designed the ''Dagor'' (aka ''Double Anastigmatic Goerz'') for Goerz (company), Goerz, a symmetric lens with six elements in two groups, made of two cemented triple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emil Von Höegh
Emil von Höegh (10 May 1865 – 29 January 1915) was an optical lens designer, known for inventing the first double anastigmatic camera lens A camera lens, photographic lens or photographic objective is an optical lens (optics), lens or assembly of lenses (compound lens) used in conjunction with a camera body and mechanism to Imaging, make images of objects either on photographic film ... called Dagor in 1892. In the same year, he began working for the German lens manufacturer Goerz, where he became the chief optical designer. At Goerz, he developed multiple lens designs, including the Höegh meniscus and Celor. He left the company in 1902. The mountain Mount Hoegh in Antarctica is named in his honour. References 1865 births 1915 deaths Instrument makers People from the German Empire {{design-bio-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooke Optics
Cooke Optics Ltd. is a camera lens manufacturing company based in Leicester. History The foundation of Cooke Optics is coincident with Taylor, Taylor and Hobson (TTH) in 1886, as the sole activity of TTH was the manufacture of lenses under the Cooke branding. Administratively speaking, Cooke Optics is a spin-off of Taylor-Hobson, created after Taylor-Hobson shifted its focus to metrology instruments. The brand name Cooke originally came from the company T. Cooke & Sons of York, a manufacturer of telescopes. The optical manager of that company, H. Dennis Taylor (no relation), devised the Cooke triplet lens in the 1890s. Cooke of York was not interested in the manufacture of camera lenses, and licensed this design and others to TTH. Subsequently many of TTH's own designs, though unconnected with Cooke of York, also carried the Cooke brand. The Cooke triplet lens was also made under licence by Voigtländer and other companies. Throughout the twentieth century TTH produced a ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celor Lens
A Celor lens (also known as a symmetric dialyte) is a highly corrected lens A lens is a transmissive optical device that 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'') ... of the Dialyt type, designed for process photography, involving reproduction at or near 1:1 scale. Design It was developed in 1898 by Emil von Hoegh, as a development of his earlier ''Dagor'' lens (1892) designed for the German company Goerz. It was originally named the ''Double Anastigmat Goerz agorType B'', sold in both and versions; in 1904, the faster version was renamed to the ''Celor'' and the version was renamed to the ''Syntor''. Similar four-element air-spaced symmetric dialyte lenses were released by Steinheil (''Unofocal'', 1901), Kodak, and Taylor, Taylor & Hobson (''Aviar'', 1917). References Photographic lenses {{optics-s ... [...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] |
