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.
The following list comprises significant milestones in the development of photography technology.
Agfa-Gevaert N.V. (Agfa) is a Belgian-German multinational corporation that develops, manufactures, and distributes analogue and digital imaging products, software, and systems.
ORWO is a registered trademark of the company ORWO Net GmbH, based in Wolfen and is also traditionally known for black-and-white film products, made in Germany and sold under the ORWO brand.
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.
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. Reversal film is produced in various sizes, from 35 mm to roll film to 8×10 inch sheet film.
Colour photography is photography that uses media capable of capturing and reproducing colors. By contrast, black-and-white or gray-monochrome photography records only a single channel of luminance (brightness) and uses media capable only of showing shades of gray.
Color print film is used to produce color photographic prints, which date to the early 20th century. Initially a two-color process, it became three-color, more accurate, and more durable with the 1935 introduction of Eastman Kodak’s Company’s Kodachrome film, followed a year later Agfa Company’s Agfacolor. Color print film is the most common type of photographic film in consumer use. Print film produces a negative image when it is developed, requiring it to be reversed again when it is printed onto photographic paper.
Ansco was the brand name of a photographic company based in Binghamton, New York, which produced photographic films, papers and cameras from the mid-19th century until the 1980s.
A chromogenic print, also known as a C-print or C-type print, a silver halide print, or a dye coupler print, is a photographic print made from a color negative, transparency or digital image, and developed using a chromogenic process. They are composed of three layers of gelatin, each containing an emulsion of silver halide, which is used as a light-sensitive material, and a different dye coupler of subtractive color which together, when developed, form a full-color image.
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.
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.
Technicolor is a family of color motion picture processes. The first version, Process 1, was introduced in 1916, and improved versions followed over several decades.
Gevacolor is a color motion picture process. It was introduced in 1947 by Gevaert in Belgium, and an affiliate of Agfacolor. The process and company flourished in the 1950s as it was suitable for on location shooting. Both the companies merged in 1964 to form Agfa-Gevaert, and continued producing film stock till the 1980s.
Kurt von Holleben was a German chemist working for Agfa-Gevaert Technical-Scientific Laboratory as the head of the colour screen research group, overseeing development of Additive color screens (kornraster) for the Agfa-Farbenplatte glass plates (1916), and film based Agfacolor (1932) and Agfacolor Ultra (1934) ranges.
