n.a still picture formed on a light-sensitive surface using an optical system and fixed by a photochemical processSchwartz 1995, 44While the visual authority of the photograph is now increasingly undermined by the wizardry of digital technology, the “truthfulness of facts” in a photograph has always been presumed to reside in its verisimilitude. Ever since Paul Delaroche purportedly exclaimed, “From today, painting is dead,” the photograph has been perceived as an objective record of reality, the product of a mechanical and therefore neutral means of documentation. . . . Photographs derive the authority of their content from realism and accuracy, what J. B. Harley calls “talismans” of authority; archival photographs convey their message through function and context. . . . The photograph is neither truth nor reality, but a representation willed into existence for a purpose and mediated by the persons concurring in its formation.Piñar 2003, 166All images constitute a record, irrespective of the value we may attach to the information they contain. The unique property of photographic records reside in their ability to capture a moment in time and to highlight the inevitable passing of time. Although the setting and depth of vision that are chosen already imply a certain voluntary or arbitrary selection, the photographic lens perceives and records the space in a homogeneous manner and it is this global view that can provide us with useful information, sometimes capturing details not even intended by the photographer himself.an image rendered using a camera
Most traditional photographic processes use a silver halide as the light-sensitive material, although light-sensitive salts of copper, iron, and uranium have been used as well. The silver halide is reduced to metallic silver in black-and-white photographs and is used to form a dye in color photographs. In the nineteenth century, collodion was commonly used as a binder for negatives, prints, ambrotypes, and tintypes, and albumen was the most common binder for prints. Most modern photographic processes use gelatin to bind the silver halide to a film, paper, or glass support.Technically, a photograph1 is distinguished from a print1, in which the image is formed mechanically rather than photochemically. However, print3 is commonly used to describe images originally made with a camera but reproduced using a photomechanical process, such as a halftone or a Woodburytype. Such images were, at some point, a photograph before reproduction. However, digital photographs now capture and record images that are printed using a nonphotographic print process.