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Washing (photography)
In photography, washing is an important part of all film processing and printmaking processes. After materials have been fixed, washing removes unwanted and exhausted processing chemicals which, if left in situ, may cause deterioration and destruction of the image. A disadvantage of the use of thiosulfate as a fixer is its ability to dissolve elemental silver at a very slow rate. If films or papers are inadequately washed after fixing, any residual fixer can slowly bleach or stain the photographic image. For prints on high grade fibre papers, a period of continuous washing in clean, cold water for up to 40 minutes may be required. For modern plastic (resin) coated papers, washing for as little as 2 minutes in warm water can be sufficient to eliminate residual fixer. Washing aids (also called hypo clearing agents) can be used to make the process of removing fixer faster and more thorough. A quick, water-saving, and archival technique for washing film fixed ''with nonhardening fixer'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Fixer
Photographic fixer is a mixture of chemicals used in the final step in the photographic processing of film or paper. The fixer stabilises the image, removing the unexposed silver halide remaining on the photographic film or photographic paper, leaving behind the reduced metallic silver that forms the image. By fixation, the film or paper is insensitive to further action by light. Without fixing, the remaining silver halide would darken and cause fogging of the image. Chemistry Fixation is commonly achieved by treating the film or paper with a solution of thiosulfate salt. Popular salts are sodium thiosulfate—commonly called hypo—and ammonium thiosulfate—commonly used in modern rapid fixer formulae. Fixation by thiosulfate involves these chemical reactions (X = halide, typically Br−):Karlheinz Keller et al. "Photography" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. . :AgX + 2 S2O32− → g(S2O3)2sup>3− + X− :AgX + 3 S2O32− → ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastic
Plastics are a wide range of synthetic polymers, synthetic or Semisynthesis, semisynthetic materials composed primarily of Polymer, polymers. Their defining characteristic, Plasticity (physics), plasticity, allows them to be Injection moulding, molded, Extrusion, extruded, or Compression molding, pressed into a diverse range of solid forms. This adaptability, combined with a wide range of other properties such as low weight, durability, flexibility, chemical resistance, low toxicity, and low-cost production, has led to their widespread use around the world. While most plastics are produced from natural gas and petroleum, a growing minority are produced from renewable resources like polylactic acid. Between 1950 and 2017, 9.2 billion metric tons of plastic are estimated to have been made, with more than half of this amount being produced since 2004. In 2023 alone, preliminary figures indicate that over 400 million metric tons of plastic were produced worldwide. If global trends ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ilford Photo
Harman Technology Limited, trading as Ilford Photo, is a UK-based manufacturer of photographic materials known worldwide for its Ilford branded black-and-white film, papers and chemicals and other analog photography supplies. Historically it also published the '' Ilford Manual of Photography'', a comprehensive manual of everything photographic, including the optics, physics and chemistry of photography, along with recipes for many developers. Under the ownership of the industrial conglomerate ICI in the 1960s, the company produced a range of Ilfochrome (Cibachrome) and Ilfocolor colour printing materials at a new plant in Switzerland developed in partnership with the Swiss company CIBA-Geigy, which later acquired ICI's shares. By the 2000s, as the UK/Swiss company Ilford Imaging, the decline of the film market saw the UK company in receivership by 2004, but rescued by a management buy-out, Harman Technology Ltd, which today continues the production of traditional black-and-w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Film Reticulation
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] |
