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In motion pictures, Kodak's Kodacolor brand was originally associated with an early lenticular (additive color) color motion picture process, first introduced in 1928 for 16mm film. [1] The process was based on the Keller-Dorian system of color photography.
The process used a special panchromatic black-and-white film stock, oriented with the emulsion away from the lens. [2] The film base was embossed along the length of the film with microscopic lenticular bands. These lenticles were precisely shaped to focus light directly onto the emulsion in parallel strips along the length of the film from three color strips in a filter placed over the lens. A record of the color content in black and white was thereby created and could be reconstituted by projecting the film through an identical filter. The three colored stripes (red, green and blue-violet) of the filter had to be precisely oriented parallel to the film length. When an exposure was made, the varying proportion of each color reflected from the subject passed through the filter and was recorded on the film beneath each of the embossed lenticular bands as areas of strips in groups of three, each strip varying in density according to the received color value. (Dufaycolor used similar principles, but had the filter as part of the film itself).
Filming required the camera to be used at f/1.9 only, so that the striped filter worked correctly. The original Kodacolor film required an exposure of about a 1/30 second at f/1.9 in bright sunlight representing a film 'speed' (sensitivity) in modern terms of about 0.5 ISO. The physical movement of the film through the gate (frame-advance) requires additional time. The later Super Sensitive Kodacolor could be used "outdoors in any good photographic light, and even indoors under favourable conditions." Because an iris diaphragm might interfere with the projected area of the filter bands, when exposure control was required in very bright light, it had to be accomplished with neutral density filters, which were provided as part of the filter set.
To project the film a projector was required fitted with the Kodacolor Projection Filter, which is identical in effect to the filter fitted to the camera. The black and white lenticular image on the film is reconstituted into a natural color picture on the screen. As with most color processes involving a lenticular image, the pattern intrudes as visible lines on the projected image. Due to the fact that each color band in the filter is sharp-cutting, two-thirds of the light from the projection source is absorbed, so there is noticeable light loss.
While Kodacolor was a popular color home movie format, it had several drawbacks. It was not possible to make duplicates, special film was necessary to shoot with, and while the additive image was colorful and clear, the greater light absorption from the use of additive filters required brighter light sources to project, and was not practical to project over very long distances.
Lenticular Kodacolor was phased out after the introduction of 16 mm Kodachrome film in 1935.
Film stock is an analog medium that is used for recording motion pictures or animation. It is recorded on by a movie camera, developed, edited, and projected onto a screen using a movie projector. It is a strip or sheet of transparent plastic film base coated on one side with a gelatin emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast and 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 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 developed into a visible photograph. In addition to visible light, all films are sensitive to X-rays and high-energy particles. Most are at least slightly sensitive to invisible ultraviolet (UV) light. Some special-purpose films are sensitive into the infrared (IR) region of the spectrum.
35 mm film is a film gauge used in filmmaking, and the film standard. In motion pictures that record on film, 35 mm is the most commonly used gauge. The name of the gauge is not a direct measurement, and refers to the nominal width of the 35 mm format photographic film, which consists of strips 1.377 ± 0.001 inches (34.976 ± 0.025 mm) wide. The standard image exposure length on 35 mm for movies is four perforations per frame along both edges, which results in 16 frames per foot of film.
The following list comprises significant milestones in the development of photography technology.
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 sold process-paid in the United States until 1954 when a legal ruling prohibited this. Elsewhere, this arrangement continued.
In photography, reversal film is a type of photographic film that produces a positive image on a transparent base. The film is processed to produce transparencies or diapositives instead of negatives and prints. Reversal film is produced in various sizes, from 35 mm to roll film to 8×10 inch sheet film.
Color photography is photography that uses media capable of capturing and reproducing colors. By contrast, black-and-white (monochrome) photography records only a single channel of luminance (brightness) and uses media capable only of showing shades of gray.
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.
Panchromatic emulsion is a type of black-and-white photographic emulsion that is sensitive to all wavelengths of visible light.
Color motion picture film refers both to unexposed color photographic film in a format suitable for use in a motion picture camera, and to finished motion picture film, ready for use in a projector, which bears images in color.
Duplitized film was a type of motion picture print film stock used for some two-color natural color processes. It was introduced by Eastman Kodak around 1913. The stock was of standard gauge and thickness, but it had a photographic emulsion coated on both sides of the film base instead of on one surface only.
Keller-Dorian cinematography was a French technique from the 1920s for filming movies in color, using a lenticular process to separate red, green and blue colors and record them on a single frame of black-and-white film. Keller-Dorian was primarily a manufacturer of paper and aluminum foil. It was granted 38 patents. While researching how to create dies to color aluminum foil, they accidentally stumbled on this cinematography technique. This additive color system differs from other systems, for example Technicolor, which divided the colors into more than one frame on one or more pieces of film.
Dufaycolor is an early British additive colour photographic film process, introduced for motion picture use in 1932 and for still photography in 1935. It was derived from Louis Dufay's Dioptichrome plates, a glass-based product for colour still photography, introduced in France in 1909. Both Dioptichrome and Dufaycolor worked on the same principles as the Autochrome process, but achieved their results using a layer of tiny colour filter elements arrayed in a regular geometric pattern, unlike Autochrome's random array of coloured starch grains. The manufacture of Dufaycolor film ended in the late 1950s.
Polavision was an "instant" color home movie system launched by Polaroid in 1977.
In still photography, Kodak's Kodacolor brand has been associated with various color negative films since 1942. Kodak claims that Kodacolor was "the world's first true color negative film". More accurately, it was the first color negative film intended for making paper prints: in 1939, Agfa had introduced a 35 mm Agfacolor negative film for use by the German motion picture industry, in which the negative was used only for making positive projection prints on 35 mm film. There have been several varieties of Kodacolor negative film, including Kodacolor-X, Kodacolor VR and Kodacolor Gold.
Dye transfer is a continuous-tone color photographic printing process. It was used to print Technicolor films, as well as to produce paper colour prints used in advertising, or large transparencies for display.
In bipack color photography for motion pictures, two strips of black-and-white 35 mm film, running through the camera emulsion to emulsion, are used to record two regions of the color spectrum, for the purpose of ultimately printing the images, in complementary colors, superimposed on one strip of film. The result is a multicolored projection print that reproduces a useful but limited range of color by the subtractive color method. Bipack processes became commercially practical in the early 1910s when Kodak introduced duplitized film print stock, which facilitated making two-color prints.
Photographic film is a strip or sheet of transparent plastic film base coated on one side with a gelatin emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast, and resolution of the film.
Technicolor is a series of color motion picture processes, the first version dating to 1916, and followed by improved versions over several decades.
The Kodak Cine Special 16mm Cameras (CKS) are a family of precision, versatile, spring-wound 16mm silent movie cameras produced by Eastman Kodak from the 1930s to the 1960s, and intended for advanced consumers and industry professionals. While its rectangular format was typical of earlier Kodak 16 mm cameras, the CKS 'box' was formed by two joined sections: the spring motor half with the user controls, winding cranks, and gear work to the shutter. The other half was a film magazine which docked to the motor. This allowed the cinematographer to pre-load multiple magazines of film for quick interchange of film.
