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HALATION
An anti-halation backing is a layer found in many photographic films—and almost all film intended for motion picture cameras—usually a coating on the back of the film base, though it is sometimes incorporated between the light-sensitive emulsion and the base. Its purpose is to absorb light that passes through the emulsion, thus preventing any light from being reflected back through the emulsion from the rear surface of the base, or from anything behind the film, such as the pressure plate of the camera. This prevents a halo-like effect (halation) from forming around bright points or edges in the image. Still cameras, which handle less film and thus contend with less wear, typically hold their film in the gate with components painted or treated to be black, so reflections are less of an issue and few still films made use of anti-halation backings. The notable exception was Kodak's Kodachrome, which incorporated such a backing to aid with a very sensitive innermost layer. The ... [...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. 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 rays, and particle radiation, high-energy particles. Unmodified silver halide crys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Film Base
A film base is a transparent substrate which acts as a support medium for the photosensitive emulsion that lies atop it. Despite the numerous layers and coatings associated with the emulsion layer, the base generally accounts for the vast majority of the thickness of any given film stock. Since the late 19th century, there have been three major types of film base in use: nitrate (until about 1951), acetate, and polyester. Nitrate In the literature of photography "nitrate" is used as a synonym for the chemical nitrocellulose. It is also referred to as "cellulose nitrate". Nitrocellulose is guncotton, the first replacement propellant for gun powder in firearms. Film stock with a nitrate base was the first transparent flexible plasticized base commercially available, thanks to celluloid developments by John Carbutt, Hannibal Goodwin, and Eastman Kodak in the 1880s. Eastman was the first to manufacture the film stock for public sale, in 1889. Unfortunately, nitrate also had the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Emulsion
Photographic emulsion is a light-sensitive colloid used in film-based photography. Most commonly, in silver-gelatin photography, it consists of silver halide crystals dispersed in gelatin. The emulsion is usually coated onto a substrate of glass, films (of cellulose nitrate, cellulose acetate or polyester), paper, or fabric. Photographic emulsion is not a true emulsion, but a suspension of solid particles (silver halide) in a fluid (gelatin in solution). However, the word ''emulsion'' is customarily used in a photographic context. Gelatin or gum arabic layers sensitized with dichromate used in the dichromated colloid processes carbon and gum bichromate are sometimes called ''emulsions''. Some processes do not have emulsions, such as platinum, cyanotype, salted paper, or kallitype. Components Photographic emulsion is a fine suspension of insoluble light-sensitive crystals in a colloid sol, usually consisting of gelatin. The light-sensitive component is one or a mixture o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halo (optical Phenomenon)
A halo is an optical phenomenon produced by light (typically from the Sun or Moon) interacting with ice crystals suspended in the atmosphere. Halos can have many forms, ranging from colored or white rings to arcs and spots in the sky. Many of these appear near the Sun or Moon, but others occur elsewhere or even in the opposite part of the sky. Among the best known halo types are the circular halo (properly called the 22° halo), light pillars, and sun dogs, but many others occur; some are fairly common while others are extremely rare. The ice crystals responsible for halos are typically suspended in cirrus or cirrostratus clouds in the upper troposphere (), but in cold weather they can also float near the ground, in which case they are referred to as diamond dust. The particular shape and orientation of the crystals are responsible for the type of halo observed. Light is reflected and refracted by the ice crystals and may split into colors because of dispersion. The crystals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kodachrome
Kodachrome is the brand name for a color reversal film introduced by Eastman Kodak in 1935. It was one of the first successful color materials and was used for both cinematography and still photography. For many years Kodachrome was widely used for professional color photography, especially for images intended for publication in print media. Because of its complex processing requirements, the film was initially exclusively sold process-paid in the United States: customers had to pay Kodak for the cost of development when they bought the film, and independent photography stores were prohibited from developing Kodachrome photos. To develop the film, customers had to mail film to Kodak, who mailed the developed photos back for no additional charge. In 1954, the U.S. Department of Justice found this practice to be an uncompetitive violation of antitrust law. Kodak entered into a consent decree requiring they offer Kodachrome film for sale with and without the development fee, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Processing
Photographic processing or photographic development is the chemical means by which photographic film or paper is treated after photographic exposure to produce a negative or positive image. Photographic processing transforms the latent image into a visible image, makes this permanent and renders it insensitive to light.Karlheinz Keller et al. "Photography" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. All processes based upon the gelatin silver process are similar, regardless of the film or paper's manufacturer. Exceptional variations include instant films such as those made by Polaroid and thermally developed films. Kodachrome required Kodak's proprietary K-14 process. Kodachrome film production ceased in 2009, and K-14 processing is no longer available as of December 30, 2010. Ilfochrome materials use the dye destruction process. Deliberately using the wrong process for a film is known as cross processing. Common processes All photographic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
K-14 Process
K-14 was the most recent version of the developing process for Kodak's Kodachrome transparency film before its discontinuation (the last revision having been designated Process K-14M). It superseded previous versions of the Kodachrome process used with older films (such as K-12 for Kodachrome II and Kodachrome-X). The K-14 process differed significantly from its contemporary, the E-6 process, in both complexity and length. Kodachrome film has no integral color couplers; dyes are produced during processing (each color in a separate step) by the reaction of the color couplers with the oxidised developer. Due to declining sales, Kodak discontinued production of all K-14 chemistry in 2009, concurrently with Kodachrome 64 film. Dwayne's Photo, in Parsons, Kansas, operated the last K-14 line in the world, discontinued sales on December 30, 2010; the last roll was processed on January 18, 2011. Steps The layers in the film are, top-to-bottom: blue sensitive (yellow), yellow filter, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastman Color Negative
Eastman Color Negative (ECN) is a photographic processing system created by Kodak in the 1950s for the development of monopack color negative motion picture film stock. It is part of the Eastmancolor family of products sold by Eastman Kodak. The original process, known as ECN-1, was used from the 1950s to the mid-1970s, and involved development at approximately 25°C for around 7–9 minutes. Later research enabled faster development and environmentally friendlier film and process (and thus quicker photo lab turnaround time). This process allowed a higher development temperature of 41.1°C for around three minutes. This new environmentally friendly development process is known as ECN-2. It is the standard development process for all modern motion picture color negative developing, including Fujifilm , trading as Fujifilm, or simply Fuji, is a Japanese multinational conglomerate headquartered in Tokyo, Japan, operating in the realms of photography, optics, office and medical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kodak High-Speed Infrared
Kodak High-Speed Infrared film, also known as Kodak HIE, was a popular black-and-white infrared photographic film from Kodak. The film was sensitive to the visible light spectrum (with decreased green sensitivity), infrared radiation up to 900nm in wavelength, and some ultraviolet radiation as well. The prominent blooming or "glow" often seen in the highlights of infrared photographs is an artifact of HIE and not of infrared light itself (nor even of all IR-sensitive films). This is because conventional photographic films have an anti-halation layer that absorbs scattered light, while HIE lacks this backing. As a result, Kodak HIE (which also had a completely transparent base, whereas most films have slightly gray bases) had to be loaded and unloaded in total darkness. Light can enter the film through the tail protruding from a 35mm canister and without a gray base it will be piped into the film and expose it; without an anti-halation layer any light entering the substrate through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared Photography
''Top:'' tree photographed in the near infrared range. ''Bottom:'' same tree in the visible part of the spectrum. In infrared photography, the film or image sensor used is sensitive to infrared light. The part of the spectrum used is referred to as near-infrared to distinguish it from far-infrared, which is the domain of thermal imaging. Wavelengths used for photography range from about 700 nm to about 900 nm. Film is usually sensitive to visible light too, so an infrared-passing filter is used; this lets infrared (IR) light pass through to the camera, but blocks all or most of the visible light spectrum (the filter thus looks black or deep red). ("Infrared filter" may refer either to this type of filter or to one that blocks infrared but passes other wavelengths.) When these filters are used together with infrared-sensitive film or sensors, "in-camera effects" can be obtained; false-color or black-and-white images with a dreamlike or sometimes lurid appearance kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-production
Post-production is part of the process of filmmaking, video production, audio production, and photography. Post-production includes all stages of production occurring after principal photography or recording individual program segments. The first part of the post-production process is the traditional non-linear (analog) film editing at the outset of post-production has mostly been replaced by digital or video editing software that operates as a non-linear editing (NLE) system. The advantage of being able to have this non-linear capacity is in the flexibility for editing scenes out of order, making creative changes at will, carefully shaping the film in a thoughtful, meaningful way for emotional effect. Once the production team is satisfied with the picture editing, the picture editing is said to be "locked." At this point begins the turnover process, where the picture is prepared for lab and color finishing and the sound is "spotted" and turnover to the composer and sound de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
