Photograph
From Wikipedia, the free encyclopedia
Photo by Jeff Widener (Associated Press)
A photograph (often shortened to photo) is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic imager such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of what the human eye would see. The process of creating photographs is called photography.
Motion pictures, such as film or video, are not generally considered to be sequences of photographs.
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[edit] History
The first permanent photograph was made in 1826 by a French inventor, Joseph Nicéphore Niépce, building on a discovery by Johann Heinrich Schultz (1724): that a silver and chalk mixture darkens under exposure to light. Niépce and Louis Daguerre refined this process. Daguerre discovered that exposing the silver first to iodine vapor, before exposure to light, and then to mercury fumes after the photograph was taken, could form a latent image; bathing the plate in a salt bath then fixes the image. These ideas led to the famous daguerreotype.
The daguerreotype had its problems, notably the extreme fragility of the resulting picture, and that it was a positive-only process and thus could not be re-printed. Inventors set about looking for improved processes that would be more practical. Several processes were introduced and used for a short time between Niépce's first image and the introduction of the collodion process in 1848. Collodion-based wet-glass plate negatives with prints made on albumen paper remained the preferred photographic method for some time, even after the introduction of the even more practical gelatin process in 1871. Adaptations of the gelatin process have remained the primary black-and-white photographic process to this day, differing primarily in the film material itself, originally glass and then a variety of flexible films.
Color photography is almost as old as black-and-white, with early experiments dating to John Herschel's experiments with Anthotype from 1842, and Lippmann plate from 1891. Color photography became much more popular with the introduction of Autochrome Lumière in 1903, which was replaced by Kodachrome, Ilfochrome and similar processes. For many years these processes were used almost exclusively for transparencies (in slide projectors and similar devices), but color prints became popular with the introduction of the Chromogenic negative, which is the most-used system in the C-41 process. The needs of the movie industry have also introduced a host of special-purpose systems, perhaps the most well known being the now-rare Technicolor.
[edit] Types of photographs
Non-digital photographs are produced with a two-step chemical process. In the two-step process the film holds a negative image (colors and lights/darks are inverted), which is then transferred onto photographic paper as a positive image. Another widely used film is the positive film used for producing transparencies, usually mounted in cardboard or plastic frames called slides. Slides are widely used by professionals due to their sharpness and accuracy of color rendition. Most photographs published in magazines are taken on color transparency film.
Originally all photographs were monochromatic, or hand-painted in color. Although methods for developing color photos were available as early as 1861, they did not become widely available until the 1940s or 50s, and even so, until the 1960s most photographs were taken in black and white. Since then, color photography has dominated popular photography, although the black and white format remains popular for amateur photographers and artists. Black and white film is considerably easier to develop than color.
Panoramic format Images can be taken with special cameras like the Hasselblad Xpan on standard film. Since the 1990s, panoramic photos have been available on the Advanced Photo System film. APS was developed by several of the major film manufacturers to provide a film with different formats and computerized options available, though APS panoramas were created using a mask in panorama-capable cameras, far less desirable than a true panoramic camera which achieves its effect through wider film format. APS has become less popular and will be discontinued.
Digital photos are stored on computers in various file formats, of which JPEG is the most popular. Many other graphic formats are used, including TIFF and RAW.
An archival digital print is a digital photographic process that results in an image display life of 100+ years, if displayed indoors under glass. Special acid free archival inks or pigments are printed directly on acid free archival art papers. Ultrachrome, Ilfochrome, and Archival Pigments are examples of commercial inks available for the production of archival digital prints. Velvet Fine Art Paper, 100% Rag, Canvas, Enahnced Matte, Watercolor Paper, Premium Ultra Glossy and other papers are examples of printable media used in archival digital printing. These prints are sometimes given the coined name "Giclée" if they are images from another medium such as a watercolor, acrylic or oil (a digital reproduction).
The process requires inkjet printers, IRIS printers, carbon pigment printing, or other similar processes. Epson, Canon, Hewlett-Packard, Lexmark and other manufacturers sell printers that enabling printing at home.
[edit] Famous photographs
Photography has remained the primary method of recording important visual events since its introduction in the 19th century. Improvements in film processes allowed the cameras to shrink in size and improve in quality and robustness at the same time. Movie cameras are generally larger and more fragile.
[edit] Myths and superstition
Photographs capture a life-like view of the subject whereas paintings were subject to the interpretations and level of skill of the painter. Thus, since daguerreotypes were rendered on a mirrored surface, many spiritualists also became practitioners of the new art form. Spiritualists would claim that the human image on the mirrored surface was akin to looking into one's soul. The spiritualists also believed that it would open their souls and let demons in.
[edit] Myths in rural India
A few people residing in rural India still believe that taking a photograph of a person reduces his lifetime. This myth was spread even among the educated community until the early twentieth century. The idea was abandoned only when they started seeing personalities and leaders as photographs in newspapers.
Another myth is associated with Vallalar, a saint who lived in the British era in South India, that his image could not be captured by a camera. Moreover his image when seen as a reflection in a mirror was reputed to be that of Lord Muruga, the Hindu God of war.
[edit] See also
