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Loupe
A loupe ( ) is a simple, small magnification device used to see small details more closely. They generally have higher magnification than a magnifying glass, and are designed to be held or worn close to the eye. A loupe does not have an attached handle, and its focusing lens(es) are contained in an opaque cylinder or cone. On some loupes this cylinder folds into an enclosing housing that protects the lenses when not in use. Optics Three basic types of loupes exist: * Simple lenses, generally used for low-magnification designs because of high optical aberration. * Compound lenses, generally used for higher magnifications to control optical aberration. * Prismatic, multiple lenses with prisms. Uses Loupes are used in many professions where magnification enables precision work to be done with greater efficiency and ease. Examples include surgery, dentistry, ophthalmology, the jewelry trade, gemology, questioned document examination, and watchmaking. Loupes are also somet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Clarity
Diamond clarity is the quality of diamonds that relates to the existence and visual appearance of internal characteristics of a diamond called ''inclusions'', and surface defects, called ''blemishes''. Clarity is one of the four Cs of diamond grading, the others being carat, color, and cut. Inclusions are solids, liquids, or gases that were trapped in a mineral as it formed. They may be crystals of a foreign material or even another diamond crystal, or may have produced structural imperfections, such as tiny cracks that make a diamond appear whitish or cloudy. The number, size, color, relative location, orientation, and visibility of inclusions can all affect the relative clarity of a diamond. A clarity grade is assigned based on the overall appearance of the stone under ten times magnification, which is the standard magnification for loupes used in the gem world. Most inclusions present in gem-quality diamonds do not affect the diamonds' performance or structural integrity an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BelOMO 10× Achromatic Triplet Loupe 1
BelOMA (Belarus Optical & Mechanical Association; Belarusian: , ; Russian: BelOMO or ''Bel''orusskoe ''O''ptiko-''M''echanichesckoye ''O''byedinenie - Беломо or ''Бел''орусское ''о''птико-''м''еханическое ''о''бъединение) is the leading optoelectronic device producer in Belarus, founded in 1954 as the Minsk Mechanical Factory. The main factory opened in Minsk 1957 and was named after the Soviet physicist Sergey Ivanovich Vavilov (1891–1951). At first, BelOMA made photographic equipment and lens-making machinery for state use. It now manufactures a wide range of products, including military and consumer optical products. During the 1980s it produced the Agat-18 and Agat-18K Half-frame camera, half-frame 35mm cameras, still popular among Lomography, Lomographic photographers. A joint venture with Germany, German optics maker Carl Zeiss AG, Zeiss was begun in 1995 and ended 2023/24. The firm produces lenses and optical elements for m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnifying Glass
A magnifying glass is a convex lens—usually mounted in a frame with a handle—that is used to produce a magnified image of an object. A magnifying glass can also be used to focus light, such as to concentrate the Sun's radiation to create a hot spot at the focus for fire starting. Evidence of magnifying glasses exists from antiquity. The magnifying glass is an icon of detective fiction, particularly that of Sherlock Holmes. An alternative to a magnifying glass is a sheet magnifier, which comprises many very narrow concentric ring-shaped lenses, such that the combination acts as a single lens but is much thinner. Use The convex lens of a magnifying glass can be used to produce a magnified image An image or picture is a visual representation. An image can be Two-dimensional space, two-dimensional, such as a drawing, painting, or photograph, or Three-dimensional space, three-dimensional, such as a carving or sculpture. Images may be di ... of an object. A magnify ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Watchmaking
A watchmaker is an artisan who makes and repairs watches. Since a majority of watches are now factory-made, most modern watchmakers only repair watches. However, originally they were master craftsmen who built watches, including all their parts, by hand. Modern watchmakers, when required to repair older watches, for which replacement parts may not be available, must have fabrication skills, and can typically manufacture replacements for many of the parts found in a watch. The term clockmaker refers to an equivalent occupation specializing in clocks. Most practising professional watchmakers service current or recent production watches. They seldom fabricate replacement parts. Instead they obtain and fit factory spare parts applicable to the watch brand being serviced. The majority of modern watchmakers, particularly in Switzerland and other countries in Europe, work directly for the watchmaking industry and may have completed a formal watchmaking degree at a technical school ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Questioned Document Examination
In forensic science, questioned document examination (QDE) is the examination of documents potentially disputed in a court of law. Its primary purpose is to provide evidence about a suspicious or questionable document using scientific processes and methods. Evidence might include alterations, the chain of possession, damage to the document, forgery, origin, authenticity, or other questions that come up when a document is challenged in court. Overview Many QDE involve a comparison of the questioned document, or components of the document, to a set of known standards. The most common type of examination involves handwriting wherein the examiner tries to address concerns about potential authorship. A document examiner is often asked to determine if a questioned item originated from the same source as the known item(s), then present their opinion on the matter in court as an expert witness. Other common tasks include determining what has happened to a document, determining when a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemology
Gemology or gemmology is the science dealing with natural and artificial gemstone materials. It is a specific interdisciplinary branch of mineralogy. Some jewellery, jewelers (and many non-jewelers) are academically trained gemologists and are qualified to identify and evaluate gems. History Rudimentary education in gemology for jewellers and gemologists began in the nineteenth century, but the first qualifications were instigated after the National Association of Goldsmiths of Great Britain (NAG) set up as an Education Committee for this purpose in 1908. The committee emerged as a distinct branch of NAG (named the Gemmological Association) in 1931, shortly after the incorporation of the Gemological Institute of America (GIA). In 1938 the branch was renamed as the Gemmological Association of Great Britain, before being incorporated in 1847. The organisation is now an educational charity and accredited awarding body with its courses taught worldwide. The first US graduate of Gem-A' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemological Institute Of America
The Gemological Institute of America (GIA) is a nonprofit institute based in Carlsbad, California. It is dedicated to research and education in the field of gemology and the jewelry arts. Founded in 1931, GIA's mission is to protect buyers and sellers of gemstones by setting and maintaining the standards used to evaluate gemstone quality. The institute does so through research, gem identification, diamond grading services, and a variety of educational programs. Through its library and subject experts, GIA acts as a resource of gem and jewelry information for the trade, the public and media outlets. In 1953 the GIA developed its International Diamond Grading System and the "four Cs" ( cut, clarity, color, and carat weight) as a standard to compare and evaluate the quality of diamonds. As of 2024, the institute is headquartered in Carlsbad, California, and operates in 13 countries, with 11 campuses, 9 laboratories, and 4 research centers. History GIA was founded in the 1920s by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Film
Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast, and image resolution, resolution of the film. Film is typically segmented in ''frames'', that give rise to separate photographs. The emulsion will gradually darken if left exposed to light, but the process is too slow and incomplete to be of any practical use. Instead, a very short exposure (photography), exposure to the image formed by a camera lens is used to produce only a very slight chemical change, proportional to the amount of light absorbed by each crystal. This creates an invisible latent image in the emulsion, which can be chemically photographic processing, developed into a visible photograph. In addition to visible light, all films are sensitive to ultraviolet light, X-rays, gamma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reversal Film
In photography, reversal film or slide film is a type of photographic film that produces a positive image on a transparent base. Instead of negatives and prints, reversal film is processed to produce transparencies or diapositives (abbreviated as "diafilm" or "dia" in some languages like German, Romanian or Hungarian). Reversal film is produced in various sizes, from 35 mm to roll film to 8×10 inch sheet film. A slide is a specially mounted individual transparency intended for projection onto a screen using a slide projector. This allows the photograph to be viewed by a large audience at once. The most common form is the 35 mm slide, with the image framed in a 2×2 inch cardboard or plastic mount. Some specialized labs produce photographic slides from digital camera images in formats such as JPEG, from computer-generated presentation graphics, and from a wide variety of physical source material such as fingerprints, microscopic sections, paper documents, astr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Glass
Ground glass is glass whose surface has been ground to produce a flat but rough ( matte) finish, in which the glass is in small sharp fragments. Ground glass surfaces have many applications, ranging from ornamentation on windows and table glassware to scientific uses in optics and laboratory glassware. Uses Photography In photography, a sheet of ground glass is used for the manual focusing in some still and movie cameras; the ground-glass viewer is inserted in the back of the camera, and the lens opened to its widest aperture. This projects the scene on the ground glass upside down. The photographer focuses and composes using this projected image, sometimes with the aid of a magnifying glass (or loupe). In order to see the image better, a dark cloth is used to block out light, whence came the image of the old-time photographer with his head stuck under a large black cloth. A ground glass is also used in the reflex finder of an SLR or TLR camera. In motion-picture cameras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Table
A light table is a viewing device that is used to review photographic film or artwork placed on top of it. The horizontal form of a self-standing lightbox provides even illumination of the subject from below, or through a translucent cover placed in front of a fluorescent light, which emits a small amount of heat. Some light tables may appear as large light boxes which stand horizontally against some type of support, allowing the user to lay sheets of paper— or film stock— on their work surface to easily view them while seated in a chair. Light tables can also be big and complicated affairs, with stereoscopes integrated as a self-supporting unit. This type of light table is used by Tomcat TARPS squadrons for interpreting aerial photographs. Light tables are mainly used in the trade of graphics to trace designs, especially in the world of cartoon or comics. Another use case for light tables is to review film negatives, photoliths, or any kind of artwork which can be plac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Film
A film, also known as a movie or motion picture, is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, emotions, or atmosphere through the use of moving images that are generally, since the 1930s, synchronized with sound and (less commonly) other sensory stimulations. Etymology and alternative terms The name "film" originally referred to the thin layer of photochemical emulsion on the celluloid strip that used to be the actual medium for recording and displaying motion pictures. Many other terms exist for an individual motion-picture, including "picture", "picture show", "moving picture", "photoplay", and "flick". The most common term in the United States is "movie", while in Europe, "film" is preferred. Archaic terms include "animated pictures" and "animated photography". "Flick" is, in general a slang term, first recorded in 1926. It originates in the verb flicker, owing to the flickering appearance of early films ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
