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Dye Destruction
Dye destruction or dye bleach is a photographic printing process, in which dyes embedded in the paper are bleached (destroyed) in processing. Because the dyes are fully formed in the paper prior to processing, they may be formulated with few constraints, compared to the complex dye couplers that must react in chromogenic processing. This method has allowed the use of richly colored, highly stable dyes. It is a reversal process, meaning that it is used in printing transparencies (diapositives). Ilfochrome (originally Cibachrome) is currently the only widely available dye destruction process, and is known for its intense colors and archival qualities. Older dye destruction processes included Utocolor (early 1900s) and Gasparcolor Gasparcolor was a color motion picture film system, developed in Berlin in 1933 by the Hungarian chemist Dr. Béla Gáspár ( Oraviczbánya, Transylvania 1898-1973). It used a subtractive 3-color process on a single film strip, one of the earli ... (1930s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Print
Photographic printing is the process of producing a final image on paper for viewing, using chemically sensitized paper. The paper is exposed to a photographic negative, a positive transparency (or ''slide''), or a digital image file projected using an enlarger or digital exposure unit such as a LightJet or Minilab printer. Alternatively, the negative or transparency may be placed atop the paper and directly exposed, creating a contact print. Digital photographs are commonly printed on plain paper, for example by a color printer, but this is not considered "photographic printing". Following exposure, the paper is processed to reveal and make permanent the latent image. Printing on black-and-white paper The process consists of four major steps, performed in a photographic darkroom or within an automated photo printing machine. These steps are: *Exposure of the image onto the sensitized paper using a contact printer or enlarger; * Processing of the latent image using the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dye Couplers
Dye coupler is present in chromogenic film and paper used in photography, primarily color photography. When a color developer reduces ionized (exposed) silver halide crystals, the developer is oxidized, and the oxidized molecules react with dye coupler molecules to form a dye ''in situ.'' The silver image is removed by subsequent bleach and fix processes, so the final image will consist of the dye image. Dye coupler technology has seen considerable advancement since the beginning of modern color photography. Major film and paper manufacturers have continually improved the stability of the image dye by improving couplers, particularly since the 1980s, so that archival properties of images are enhanced in newer color papers and films. Generally speaking, dye couplers for paper use are given more emphasis on the image permanence than those for film use, but some modern films (such as Fujichrome Provia Provia is a brandname for a pair of daylight-balanced color reversal films ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromogenic
In chemistry, the term chromogen refers to a colourless (or faintly coloured) chemical compound that can be converted by chemical reaction into a compound which can be described as "coloured". There is no universally agreed definition of the term. Various dictionaries give the following definitions: * A substance capable of conversion into a pigment or dye. * Any substance that can become a pigment or coloring matter, a substance in organic fluids that forms colored compounds when oxidized, or a compound, not itself a dye, that can become a dye. * Any substance, itself without color, giving origin to a coloring matter. In biochemistry the term has a rather different meaning. The following are found in various dictionaries. * A precursor of a biochemical pigment * A pigment-producing microorganism * Any of certain bacteria that produce a pigment * A strongly pigmented or pigment-generating organelle, organ, or microorganism. Applications in chemistry *In chromogenic photography, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ilfochrome
Ilfochrome (also commonly known as Cibachrome) is a dye destruction positive-to-positive photographic process used for the reproduction of film transparencies on photographic paper. The prints are made on a dimensionally stable polyester base as opposed to traditional paper base. Since it uses 13 layers of azo dyes sealed in a polyester base, the print will not fade, discolour, or deteriorate for an extended time. Accelerated aging tests conducted by Henry Wilhelm rated the process as producing prints which, framed under glass, would last for 29 years before color shifts could be detected. Characteristics of Ilfochrome prints are image clarity, color purity, and being an archival process able to produce critical accuracy to the original transparency. History Dr. Bela Gaspar created Gasparcolor, the dye bleach process upon which the Cibachrome process was originally based. It was considered vital to the war effort in the 1940s. Gaspar turned down many offers to sell the rights ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utocolor
Utocolor or Uto paper was a light-sensitive paper for color photography manufactured by Dr. J.H. Smith of Zurich, Switzerland and available by early 1907. Overview Improved versions appeared in later years. It used the direct bleach-out method of color reproduction first proposed by Louis Ducos du Hauron and Charles Cros in the late 1860s and based on the fact that a substance can only be affected by exposure to light if it absorbs some of that light.The Grotthuss-Draper law. Unstable coloring matter is therefore bleached by light of its complementary color Complementary colors are pairs of colors which, when combined or mixed, cancel each other out (lose hue) by producing a grayscale color like white or black. When placed next to each other, they create the strongest contrast for those two co ..., which it strongly absorbs, but little affected by light of its own color, which it mostly transmits or reflects. The Uto paper came coated with a mixture of cyan, magenta and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Library Of Congress
The Library of Congress (LOC) is the research library that officially serves the United States Congress and is the ''de facto'' national library of the United States. It is the oldest federal cultural institution in the country. The library is housed in three buildings on Capitol Hill in Washington, D.C.; it also maintains a conservation center in Culpeper, Virginia. The library's functions are overseen by the Librarian of Congress, and its buildings are maintained by the Architect of the Capitol. The Library of Congress is one of the largest libraries in the world. Its "collections are universal, not limited by subject, format, or national boundary, and include research materials from all parts of the world and in more than 470 languages." Congress moved to Washington, D.C., in 1800 after holding sessions for eleven years in the temporary national capitals in New York City and Philadelphia. In both cities, members of the U.S. Congress had access to the sizable collection ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gasparcolor
Gasparcolor was a color motion picture film system, developed in Berlin in 1933 by the Hungarian chemist Dr. Béla Gáspár ( Oraviczbánya, Transylvania 1898-1973). It used a subtractive 3-color process on a single film strip, one of the earliest to do so. During the 1930s and 1940s, it was used primarily in animation, notably by Oskar Fischinger (''Muratti Gets in the Act'', 1934; ''Composition in Blue'', 1935), Len Lye (''Birth of a Robot'', ''Rainbow Dance'', both 1936), and George Pal. It also saw use in live-action film, including "Colour on the Thames" (1935). William Moritz, in his article for the Fischinger Archive, gives more detail about this history of this color process. Because of the darkening political climate in Europe, his hungarian-jewish wife Elly Tardos-Taussig (Szeged 1908-) comitted suicide, Dr. Gaspar eventually moved to Hollywood and sold his patents to Technicolor and 3M. See also * Studio system A studio system is a method of filmmaking wherein t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
