Photography is the art, application and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed in many fields of science, manufacturing, and business, as well as its more direct uses for art, film and video production, recreational purposes, hobby, and mass communication.
The Autochrome Lumière is an early color photography process patented in 1903 by the Lumière brothers in France and first marketed in 1907. It was the principal color photography process in use before the advent of subtractive color film in the mid-1930s. Prior to the Lumiere brothers, Louis Ducos du Hauron utilized the separation technique to create colour images on paper with screen plates, producing natural colours through superimposition, which would become the foundation of all commercial colour photography. Descendants of photographer Antoine Lumiere, inventors Louis and Auguste Lumiere utilized Du Hauron's (1869) technique, which had already been improved upon by other inventors such as John Joly (1894) and James William McDonough (1896), making it possible to print photographic images in colour. The most broadly used form of colour photography in the early twentieth century, autochrome was cherished for its aesthetic appeal and uniqueness, which have also become its most recognizable characteristics.
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.
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.
Photographic paper is a paper coated with a light-sensitive chemical formula, used for making photographic prints. When photographic paper is exposed to light, it captures a latent image that is then developed to form a visible image; with most papers the image density from exposure can be sufficient to not require further development, aside from fixing and clearing, though latent exposure is also usually present. The light-sensitive layer of the paper is called the emulsion. The most common chemistry was based on silver salts but other alternatives have also been used.
Sergey Mikhaylovich Prokudin-Gorsky was a Russian chemist and photographer. He is best known for his pioneering work in colour photography and his effort to document early 20th-century Russia.
An enlarger is a specialized transparency projector used to produce photographic prints from film or glass negatives, or from transparencies.
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 a digital image file projected using an enlarger or digital exposure unit such as a LightJet printer. Alternatively, the negative or transparency may be placed atop the paper and directly exposed, creating a contact print. Photographs are more commonly printed on plain paper, for example by a color printer, but this is not considered "photographic printing".
Photogravure is an intaglio printmaking or photo-mechanical process whereby a copper plate is grained and then coated with a light-sensitive gelatin tissue which had been exposed to a film positive, and then etched, resulting in a high quality intaglio plate that can reproduce detailed continuous tones of a photograph.
Jonas Ferdinand Gabriel Lippmann was a Franco-Luxembourgish physicist and inventor, and Nobel laureate in physics for his method of reproducing colours photographically based on the phenomenon of interference.
The history of photography began in remote antiquity with the discovery of two critical principles: camera obscura image projection and the observation that some substances are visibly altered by exposure to light. There are no artifacts or descriptions that indicate any attempt to capture images with light sensitive materials prior to the 18th century. Around 1717 Johann Heinrich Schulze captured cut-out letters on a bottle of a light-sensitive slurry, but he apparently never thought of making the results durable. Around 1800 Thomas Wedgwood made the first reliably documented, although unsuccessful attempt at capturing camera images in permanent form. His experiments did produce detailed photograms, but Wedgwood and his associate Humphry Davy found no way to fix these images.
A chromogenic print, also known as 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.
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.
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.
In motion pictures, Kodak's Kodacolor brand was associated with an early lenticular color motion picture process, first introduced in 1928 for 16mm film. The process was based on the Keller-Dorian system of lenticular color photography.
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.
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.
The Finlay colour process was an early additive colour photography process devised by Englishman Clare L. Finlay which could produce a picture in natural colour with a single exposure.
