Photography

Description

The word "photography" was created from the Greek roots φωτός (phōtos), genitive of φῶς (phōs), "light" and γραφή (graphé) "representation by means of lines" or "drawing", together meaning "drawing with light".

Invented in the early decades of the 19th Century, photography by means of the camera seemed able to capture more detail and information than traditional media, such as painting and sculpture. Photography as a usable process goes back to the 1820s with the development of chemical photography. The first permanent photoetching was an image produced in 1822 by the French inventor Nicéphore Nièpce, but it was destroyed in a later attempt to make prints from it. Nièpce was successful again in 1825. He made the View from the Window at Le Gras, the earliest surviving photograph from nature (i.e., of the image of a real-world scene, as formed in a camera obscura by a lens), in 1826 or 1827.

Because Nièpce's camera photographs required an extremely long exposure (at least eight hours and probably several days), he sought to greatly improve his bitumen process or replace it with one that was more practical. Working in partnership with Louis Daguerre, he developed a somewhat more sensitive process that produced visually superior results, but it still required a few hours of exposure in the camera. Nièpce died in 1833 and Daguerre then redirected the experiments toward the light-sensitive silver halides, which Nièpce had abandoned many years earlier because of his inability to make the images he captured with them light-fast and permanent. Daguerre's efforts culminated in what would later be named the Daguerreotype process, the essential elements of which were in place in 1837. The required exposure time was measured in minutes instead of hours. Daguerre took the earliest confirmed photograph of a person in 1838 while capturing a view of a Paris street: unlike the other pedestrian and horse-drawn traffic on the busy boulevard, which appears deserted, one man having his boots polished stood sufficiently still throughout the approximately ten-minute-long exposure to be visible. Eventually, France agreed to pay Daguerre a pension for his process in exchange for the right to present his invention to the world as the gift of France, which occurred on August 19, 1839.

A latticed window in Lacock Abbey, England, photographed by William Fox Talbot in 1835 is may be the oldest existant photographic negative made in a camera. Meanwhile, in Brazil, Hercules Florence had already created his own process in 1832, naming it Photographie, and an English inventor, William Fox Talbot, had created another method of making a reasonably light-fast silver process image but had kept his work secret. After reading about Daguerre's invention in January of 1839, Talbot published his method and set about improving on it. At first, like other pre-daguerreotype processes, Talbot's paper-based photography typically required hours-long exposures in the camera, but in 1840 he created the calotype process, with exposures comparable to the daguerreotype. In both its original and calotype forms, Talbot's process, unlike Daguerre's, created a translucent negative which could be used to print multiple positive copies, the basis of most chemical photography up to the present day. Daguerreotypes could only be replicated by rephotographing them with a camera. Talbot's famous tiny paper negative of the Oriel window in Lacock Abbey, one of a number of camera photographs he made in the summer of 1835, may be the oldest camera negative in existence.

John Herschel made many contributions to the new field. He invented the cyanotype process, later familiar as the "blueprint". He was the first to use the terms "photography", "negative" and "positive". He had discovered in 1819 that sodium thiosulphate was a solvent of silver halides, and in 1839 he informed Talbot (and, indirectly, Daguerre) that it could be used to "fix" silver-halide-based photographs and make them completely light-fast. He made the first glass negative in late 1839.

In the March 1851 issue of The Chemist, Frederick Scott Archer published his wet plate collodion process. It became the most widely used photographic medium until the gelatin dry plate, introduced in the 1870s, eventually replaced it. There are three subsets to the collodion process; the Ambrotype (a positive image on glass), the Ferrotype or Tintype (a positive image on metal) and the glass negative, which was used to make positive prints on albumen or salted paper.

Many advances in photographic glass plates and printing were made during the rest of the 19th century. In 1884, George Eastman developed an early type of film to replace photographic plates, leading to the technology used by film cameras today.

In 1891, Gabriel Lippmann introduced a process for making natural-color photographs based on the optical phenomenon of the interference of light waves. His scientifically elegant and important but ultimately impractical invention earned him the Nobel Prize for Physics in 1908.

Black-and-white photography

All photography was originally monochrome, or black-and-white. Even after color film was readily available, black-and-white photography continued to dominate for decades, due to its lower cost and its "classic" photographic look. The tones and contrast between light and dark shadows define black and white photography. Many photographers continue to produce some monochrome images, often because of the established archival permanence of well processed silver halide based materials.

Color photography

Color photography was explored beginning in the mid-19th century. Early experiments in color required extremely long exposures (hours or days for camera images) and could not "fix" the photograph to prevent the color from quickly fading when exposed to white light.

The first permanent color photograph was taken in 1861 using the three-color-separation principle first published by physicist James Clerk Maxwell in 1855. Maxwell's idea was to take three separate black-and-white photographs through red, green and blue filters. This provides the photographer with the three basic channels required to recreate a color image.

Transparent prints of the images could be projected through similar color filters and superimposed on the projection screen, an additive method of color reproduction. A color print on paper could be produced by superimposing carbon prints of the three images made in their complementary colors, a subtractive method of color reproduction pioneered by Louis Ducos du Hauron in the late 1860s.

Russian photographer Sergei Mikhailovich Prokudin-Gorskii made extensive use of this color separation technique, employing a special camera which successively exposed the three color-filtered images on different parts of an oblong plate. Because his exposures were not simultaneous, unsteady subjects exhibited color "fringes".

The development of color photography was hindered by the limited sensitivity of early photographic materials, which were mostly sensitive to blue, only slightly sensitive to green, and virtually insensitive to red. The discovery of dye sensitization by photochemist Hermann Vogel in 1873 suddenly made it possible to add sensitivity to green, yellow and even red. Improved color sensitizers and ongoing improvements in the overall sensitivity of emulsions steadily reduced the once-prohibitive long exposure times required for color, bringing it ever closer to commercial viability.

Autochrome, the first commercially successful color process, was introduced by the Lumière brothers in 1907. Autochrome plates incorporated a mosaic color filter layer made of dyed grains of potato starch, which allowed the three color components to be recorded as adjacent microscopic image fragments. After an Autochrome plate was reversal processed to produce a positive transparency, the starch grains served to illuminate each fragment with the correct color and the tiny colored points blended together in the eye, synthesizing the color of the subject by the additive method. Autochrome plates were one of several varieties of additive color screen plates and films marketed between the 1890s and the 1950s.

Kodachrome, the first modern "integral tripack" (or "monopack") color film, was introduced by Eastman Kodak in 1935. It captured the three color components in a multilayer emulsion. One layer was sensitized to record the red-dominated part of the spectrum, another layer recorded only the green part and a third recorded only the blue. Without special film processing, the result would simply be three superimposed black-and-white images, but complementary cyan, magenta, and yellow dye images were created in those layers by adding color couplers during a complex processing procedure.

Agfa's similarly structured Agfacolor Neu was introduced in 1936. Unlike Kodachrome, the color couplers in Agfacolor Neu were incorporated into the emulsion layers during manufacture, which greatly simplified the processing. Currently available color films still employ a multilayer emulsion and the same principles, most closely resembling Agfa's product.

Instant color film, used in a special camera which yielded a unique finished color print only a minute or two after the exposure, was introduced by Polaroid in 1963.

Color photography may form images as positive transparencies, which can be used in a slide projector, or as color negatives intended for use in creating positive color enlargements on specially coated paper. The latter is now the most common form of film (non-digital) color photography owing to the introduction of automated photo printing equipment.

Digital photography

In 1981, Sony unveiled the first consumer camera to use a charge-coupled device (CCD) for imaging, eliminating the need for film: the Sony Mavica. While the Mavica saved images to disk, the images were displayed on television, and the camera was not fully digital. In 1991, Kodak unveiled the DCS 100, the first commercially available digital single lens reflex camera. Although its high cost precluded uses other than photojournalism and professional photography, commercial digital photography was born.

Digital imaging uses an electronic image sensor to record the image as a set of electronic data rather than as chemical changes on film. An important difference between digital and chemical photography is that chemical photography resists photo manipulation because it involves film and photographic paper, while digital imaging is a highly manipulative medium. This difference allows for a degree of image post-processing that is comparatively difficult in film-based photography and permits different communicative potentials and applications.

In conservation science, photography if one of the extensively used examination technique, starting from conventional black & white or colour visible light photography, to Raking light photography, Infrared photography, Ultraviolet induced fluorescence photography, microscope photography...

Synonyms and related terms

Fotographie, Foto (Deut.); photographie (Fr.); fotografia (It. ; Port.)

Additional information

• http://en.wikipedia.org/wiki/Photography

• A history of photography - From 1839 to the present, The George Eastman House Collection, Taschen, Koeln (2005)

Authority

• Maison Europeenne de la Photographie (Paris) - http://www.mep-fr.org/

• American Museum of Pphotography - http://www.photographymuseum.com/

• International Center of Photography (New York City) - http://www.icp.org/museum

• George eastman House (Rochester) - http://www.eastmanhouse.org/

• Deutsches Museum Sammlung Foto + Film (Munich) - http://www.deutsches-museum.de/sammlungen/foto-und-film/