The camera itself is based on optical principles known at least since the age of Aristotle; indeed, a filmless version was in use in the mid-1500s as a sketching device for artists. Called the camera obscura (Lat.,=dark chamber), it consisted of a small, lightproof box with a pinhole or lens on one side and a translucent screen on the opposite side. This screen registered, in a manner suitable for tracing, the inverted image transmitted through the lens. The human eye was the prototype for this device, which functioned as a primitive extension of seeing. Most experiments in photographic technology were directed toward perfecting the medium as a surrogate, more sophisticated eye.
The necessary first breakthrough in photography was in a different, not eye-centered area—that of making permanent photographic images. Employing data from the researches of Johann Heinrich Schulze—who, in 1727, discovered that silver nitrate darkened upon exposure to light—Thomas Wedgwood and Sir Humphry Davy, early in the 19th cent., created what we now call photograms. These were made by placing assorted objects on paper soaked in silver nitrate and exposing them to sunlight. Those areas of the paper covered by the objects remained white; the rest blackened after exposure to the light. Davy and Wedgwood found no way of arresting the chemical action at this stage, however, and their images lasted only a short time before darkening entirely.
Photography's basic principles, processes, and materials were discovered virtually simultaneously by a diverse group of individuals of different nationalities, working for the most part entirely independently of one another. The results of their experiments coalesced in the first half of the 19th cent., creating a tool for communication that was to become as powerful and significant as the printing press. Four men figure principally in the establishment of the rudiments of photographic science.
The French physicist, Joseph Nicéphore Niepce, made the first negative (on paper) in 1816 and the first known photograph (on metal; he called it a heliograph) in 1826. By the latter date he had directed his investigations away from paper surfaces and negatives (having invented, in the meantime, what is now called the photogravure process of mechanical reproduction) and toward sensitized metallic surfaces. In 1827 Niepce had also begun his association with Louis Jacques Mandé Daguerre, a French painter who had been experimenting along parallel lines. A partnership was formed and they collaborated until Niepce's death in 1833, after which Daguerre continued their work for the next six years. In 1839 he announced the invention of a method for making a direct positive image on a silver plate—the daguerreotype.
Daguerre's announcement was a source of dismay to the English scientist William Henry Fox Talbot, who had been experimenting independently along related lines for years. Talbot had evolved a method for making a paper negative from which an infinite number of paper positives could be created. He had also worked out an effective although imperfect technique for permanently "fixing" his images. Concerned that he might lose the rights to his own invention, the calotype process, Talbot wrote to the French Academy of Sciences, asserting the priority of his own invention. He then lost no time in presenting his researches to England's Royal Society, of which he was a distinguished member.
All three pioneers, Niepce, Daguerre, and Talbot, along with Sir John Herschel—who in 1819 discovered the suitability of hyposulfite of soda, or "hypo," as a fixing agent for sensitized paper images and who is generally credited with giving the new medium its name—deserve to share the title Inventor of Photography. Each made a vital and unique contribution to the invention of the photographic process. The process developed by Daguerre and Niepce was, in a grand gesture, purchased from them by the French government and given, free of patent restrictions, to the world. Talbot patented his own process and then published a description of it, entitled The Pencil of Nature (1844-46). This book, containing 24 original prints, was the first ever illustrated with photographs.
Daguerreotypy spread rapidly, except in England, where Daguerre had secretly patented his process before selling it to the French government. The legal problems attending the pursuit of photography as a profession account in part for the widespread influence of amateurs (e.g., Nadar, the French pioneer photographer) on the early development of the medium. The popularity of the daguerreotype is attributable to two principal factors. The first of these was the Victorian passion for novelty and for the accumulation of material objects, which found its perfect paradigm in these silvery, exquisitely detailed miniatures. The second was the greatly increasing demand from a rising middle class for qualitatively good but—compared to a painter's fee—inexpensive family portraits. The cheaper tintype eventually made such likenesses available to all.
The principal shortcoming of the daguerreotype and its variants was inherent in its nature as a direct positive. Unique and unreproducible, it could not serve for the production of any image intended for wide distribution. This factor, combined with the lengthy exposure time necessitated by the process, restricted its function to portraiture. The vast majority of surviving daguerreotypes are portraits; images of any other subject are exceedingly rare. Nevertheless, for 20 years the daguerreotype completely overshadowed the greater utility of the calotype. In the United States, where it was equally popular, the daguerreotype was promoted by John W. Draper and Samuel F. B. Morse.
The calotype's paper negative made possible the reproduction of photographic images. The unavoidably coarse paper base for the negative, however, eliminated the delicate detail that made the daguerreotype so appealing. This lack of precision was understood and used to advantage by the Scottish painter David Octavius Hill and his assistant, Robert Adamson. From 1843 to 1848 they made an extensive series of calotype portraits of Scottish clergymen, intended to serve only as studies for a group portrait in oils, that stands today among the major bodies of work in the medium. Hill and Adamson composed their portraits in broad planes, juxtaposing bold masses of light and dark, creating works that are monumental in feeling despite their small size.
The dilemma of detail versus reproducibility was resolved in 1851 by an Englishman, Frederick Scott Archer, who introduced the collodion process. This method, also known as the "wet plate" technique, involved coating a glass plate with silver iodide in suspension, exposing it while still wet, and developing it immediately. Once fixed and dried, the glass plate was covered with a thin, flexible film containing the negative image, the definition and detail of which approached that of the daguerreotype. As this process merged the advantages of both its predecessors, it was universally adopted within a very short time.
With the advent of the collodion process came mass production and dissemination of photographic prints. The inception of these visual documents of personal and public history engendered vast changes in people's perception of history, of time, and of themselves. The concept of privacy was greatly altered as cameras were used to record most areas of human life. The ubiquitous presence of photographic machinery eventually changed humankind's sense of what was suitable for observation. The photograph was considered incontestable proof of an event, experience, or state of being.
To fulfill the mounting and incessant demand for more images, photographers spread out to every corner of the world, recording all the natural and manufactured phenomena they could find. By the last quarter of the 19th cent. most households could boast respectable photographic collections. These were in three main forms: the family album, which contained cabinet portraits and the smaller cartes-de-visite and tintypes; scrapbooks containing large prints of views from various parts of the world; and boxes of stereoscope cards, which in combination with the popular stereo viewer created an effective illusion of three-dimensionality.
A number of photographers, including Timothy O'Sullivan, J. K. Hillers, and W. H. Jackson, accompanied exploratory expeditions to the new frontiers in the American West, while John Thomson returned from China and Maxime Du Camp from Egypt with records of vistas and peoples never before seen by Western eyes. Roger Fenton, who photographed the Crimean conflict, and Mathew Brady's photographic corps, who documented the American Civil War, provided graphic evidence of the hellishness of combat.
E. J. Marey, the painter Thomas Eakins, and Eadweard Muybridge all devised means for making stop-action photographs that demonstrated the gap between what the mind thinks it sees and what the eye actually perceives. Muybridge's major work, Animal Locomotion (1887), remains a basic source for artists and scientists alike. As accessory lenses were perfected, the camera's vision extended both telescopically and microscopically; the moon and the microorganism became accessible as photographic images.
The introduction of the halftone process (see photoengraving; printing) in 1881 made possible the accurate reproduction of photographs in books and newspapers. In combination with new improvements in photographic technology, including dry plates and smaller cameras, which made photographing faster and less cumbersome, the halftone made immediate reportage feasible and paved the way for news photography. George Eastman's introduction in 1888 of roll film and the simple Kodak box camera provided everyone with the means of making photographs for themselves. Meanwhile, studies in sensitometry, the new science of light-sensitive materials, made exposure and processing more practicable.
The fight to certify photography as a fine art has been among the medium's dominant philosophical preoccupations since its inception. Photography's legitimacy as an art form was challenged by artists and critics, who seized upon the mechanical and chemical aspects of the photographic process as proof that photography was, at best, a craft. Perhaps because so many painters came to rely so heavily on the photograph as a source of imagery, they insisted that photography could only be a handmaiden to the arts.
To prove that photography was indeed an art, photographers at first imitated the painting of the time. Enormous popularity was achieved by such photographers as O. J. Rejlander and Henry Peach Robinson, who created sentimental genre scenes by printing from multiple negatives. Julia Margaret Cameron blurred her images to achieve a painterly softness of line, creating a series of remarkably powerful soft-focus portraits of her celebrated friends.
In opposition to the painterly aesthetic in photography was P. H. Emerson and other early advocates of what has since become known as "straight" photography. According to this approach the photographic image should not be tampered with or subjected to handwork or other affectations lest it lose its integrity. Emerson proposed this philosophy in his controversial and influential book, Naturalistic Photography (1889). Appropriately, Emerson was the first to recognize the importance of the work of Alfred Stieglitz, who battled for photography's place among the arts during the first part of the 20th cent.
In revolt against the entrenched imitation of genre painting known as "salon" photography, Stieglitz founded a movement which he called the Photo-Secession, related to the radical secession movements in painting. He initiated publication of a magazine, Camera Work (1903-17), which was a forum for the Photo-Secession and for enlightened opinion and critical thought in all the arts. It remains the most sumptuously and meticulously produced photographic quarterly in the history of the medium. In New York City, Stieglitz opened three galleries, the first (1908-17) called "291" (from its address at 291 Fifth Ave.), then the Intimate Gallery (1925-30), and An American Place (1930-46), where photographic work was hung beside contemporary, often controversial, work in other media.
Stieglitz's own photographs and those of several other Photo-Secessionists—Edward Steichen, one of his early protégés; Frederick Evans, the British architectural photographer; and the portraitist Alvin L. Coburn—adhered with relative strictness to a "straight" aesthetic. The quality of their works, despite a pervasive self-consciousness, was consistently of the highest craftsmanship. Stieglitz's overriding concern with the concept "art for art's sake" kept him, and the audience he built for the medium, from an appreciation of an equally important branch of photography: the documentary.
The power of the photograph as record was demonstrated in the 19th cent., as when William H. Jackson's photographs of the Yellowstone area persuaded the U.S. Congress to set that territory aside as a national park. In the early 20th cent. photographers and journalists were beginning to use the medium to inform the public on crucial issues in order to generate social change.
Taking as their precedents the work of such men as Jackson and reporter Jacob Riis (whose photographs of New York City slums resulted in much-needed legislation), documentarians like Lewis Hine and James Van DerZee began to build a photographic tradition whose central concerns had little to do with the concept of art. The photojournalist sought to build, strengthen, or change public opinion by means of novel, often shocking images. The finished form of the documentary image was the inexpensive multiple, the magazine or newspaper reproduction. For a time the two traditions, art photography and documentary photography, appeared to be merged within the work of one man, Paul Strand. Strand's works combined a documentary concern with a lean, modernist vision related to the avant-garde art of Europe.
Seeking to determine the particular aesthetics of photography, the American Berenice Abbott and the Frenchmen Eugène Atget, André Kertész, and Henri Cartier-Bresson developed intensely personal styles. The exponents of surrealism in France and of futurism in Italy and the various German art movements that were focused in the Bauhaus all explored the medium of photography. The international exhibition "Film und Foto," held in Stuttgart in 1929, helped to make formal a purely photographic aesthetic. The works exhibited combined elements of functionalism and abstraction. Photographic subject matter shifted from the past to the present—a present of new forms in machinery and architecture, new concern with the experience of the working classes, and a new interest in the timeless forms of nature.
In California during the 1920s and 30s Edward Weston and a handful of kindred spirits founded the f/64 group, taking their name from the smallest lens opening, that which provides the greatest precision of line and detail. This small and unofficial group—which included Imogen Cunningham, Ansel Adams, and Willard Van Dyke—came to dominate photographic art, overshadowing the pictorial aesthetic. They and their imitators eschewed all post-exposure handwork, and worked with 8 × 10-in. view cameras in order to obtain the largest possible negatives from which to make straightforward contact prints. They limited their subject matter to static things: the still life, the distant or closely viewed landscape, and the formal portrait. The influential teacher Minor White became known for his poetic, visionary work related in technique to this straight approach.
The development of the 35-mm or "candid" camera by Oskar Barnack of the Ernst Leitz company, first marketed in 1925, made documentarians infinitely more mobile and less conspicuous, while the manufacture of faster black-and-white film enabled them to work without a flash in situations with a minimum of light. Color film for transparencies (slides) was introduced in 1935 and color negative film in 1942. Portable lighting equipment was perfected, and in 1947 the Polaroid Land camera, which could produce a positive print in seconds, was placed on the market. All of these technological advances granted the photojournalist enormous and unprecedented versatility.
The advent of large-circulation picture magazines, such as Life (begun 1936) and Look (begun 1937), provided an outlet and a vast audience for documentary work. At the same time a steady stream of convulsive national and international events provided a wealth of material for the extended photo-essay, the documentarian's natural mode. One of these was the Great Depression of the 1930s, which proved to be the source of an important body of documentary work. Under the leadership of Roy Stryker, the photographic division of the Farm Security Administration (FSA) began to make an archive of images of America during this epoch of crisis. Walker Evans, Arthur Rothstein, Russell Lee, and Dorothea Lange of the FSA group photographed the cultural disintegration generated by the Depression and the concomitant disappearance of rural lifestyles.
With the coming of World War II photographers, including Margaret Bourke-White, Edward Steichen, W. Eugene Smith, Lee Miller, and Robert Capa, documented the global conflict. The war was a stimulus to photography in other ways as well. From the stress analysis of metals to aerial surveillance, the medium was a crucial tool in many areas of the war effort, and, in the urgency of war, numerous technological discoveries and advances were made that ultimately benefited all photographers.
After the war museums and art schools opened their doors to photography, a trend that has continued to the present. Photographers began to break free of the oppressive strictures of the straight aesthetic and documentary modes of expression. As exemplified by Robert Frank in his highly influential book-length photo-essay, The Americans (1959), the new documentarians commenced probing what has been called the "social landscape," often mirroring in their images the anxiety and alienation of urban life. Such introspection naturally led to an increasingly personal form of documentary photography, as in the works of J. H. Lartigue and Diane Arbus.
Many young photographers felt little inhibition against handwork, collage, multiple images, and other forms that were anathema to practitioners of the straight aesthetic. Since the 1960s photography has become an increasingly dominant medium within the visual arts. Many painters and printmakers, including Andy Warhol, Robert Rauschenberg, and David Hockney have blended photography with other modes of expression, including computer imaging in mixed media compositions at both large and small scale. Contemporary photographers who use more traditional methods to explore non-traditional subjects include Cindy Sherman and Richard Prince.
The 1990s brought the first attempt to provide a fully integrated photographic system. Aimed at the amateur photographer, the Advanced Photo System (APS) was developed by an international consortium of camera and film manufacturers. The keystone of the new system is a magnetic coating that enables the camera, film, and photofinishing equipment to communicate. The cameras are self-loading, can be switched among three different formats (classic, or 4 by 6 in.; hi vision, or 4 by 7 in.; and panoramic, or 4 by 11.5 in.), and are fully automatic (auto-focus, auto-exposure—"point-and-shoot"). The film is a new, smaller size (24 mm), has an improved polyester plastic base, and two magnetic strips that record the exposure and framing parameters for each picture and allow the user to add a brief notation to each frame. The photofinishing equipment can read the magnetic data on the film and adjust the developing of each negative to compensate for the conditions. After processing, the negatives (still encased in the cassette) are returned along with the photographs and an index sheet of thumbnail-size contact prints from which reprints and enlargements can be selected.
In the contemporary world the practical applications of the photographic medium are legion: it is an important tool in education, medicine, commerce, criminology, and the military. Its scientific applications include aerial mapping and surveying, geology, reconnaissance, meteorology, archaeology, and anthropology. New techniques such as holography, a means of creating a three-dimensional image in space, continue to expand the medium's technological and creative horizons. In astronomy the charge coupled device (CCD) can detect and register even a single photon of light.
By the end of the 20th cent. digital imaging and processing and computer-based techniques had made it possible to manipulate images in many ways, creating revolutionary changes in photography. Digital technology allowed for a fundamental change in the nature of photographic technique. Instead of light passing through a lens and striking emulsion on film, digital photography uses sensors and color filters. In one technique three filters are arranged in a mosaic pattern on top of the photosensitive layer. Each filter allows only one color (red, green, or blue) to pass through to the pixel beneath it. In the other technique, three separate photosensitive layers are embedded in silicon. Since silicon absorbs different colors at different depths, each layer allows a different color to pass through. When stacked together, a full color pixel results. In both techniques the photosensitive material converts images into a series of numbers that are then translated back into tonal values and printed. Using computers, various numbers can easily be changed, thus altering colors, rearranging pictorial elements, or combining photographs with other kinds of images. Some digital cameras record directly onto computer disks or into a computer, where the images can be manipulated at will.
See B. Newhall, The History of Photography: 1839 to the Present Day (5th rev. ed. 1982); R. Bolton, Contest of Meaning (1992); G. Batchen, Burning with Desire: The Conception of Photography (1999); J. Szarkowski, Looking at Photographs (1999); M. J. Langford, Basic Photography (2001); T. Ang, Digital Photography: An Introduction (2003). Among the many outstanding volumes of collected photographs are E. Steichen, ed., The Family of Man (1955) and American Album (1968; comp. by the ed. of American Heritage); V. Goldberg, Photography in Print (1988); W. J. Mitchell, The Reconfigured Eye: Visual Truth in the Post-Photographic Age (1993).
See catalog of his work (Metropolitan Museum of Art, 1979).
See his essays (ed. by R. Haas, 1972).
Since ethyl alcohol boils at a lower temperature than water, a common application of the process of distillation is to produce strong alcoholic drinks. Usually a still used for this purpose is made of copper, since it removes sulfur-based compounds from the alcohol that would make it unpleasant to drink. Modern stills are made of stainless steel with copper innards (piping, for example, will be lagged with copper along with copper plate inlays along still walls). Using this combination of metals is much cheaper as it prevents erosion of the entire vessel and lowers copper levels in the waste product (which in large distilleries is processed to become animal feed). All copper stills will require repairs about every 8 years because of copper erosion from the compounds it is designed to remove; this erosion is therefore unavoidable. The alcohol industry was the first to use anything close to a modern distillation apparatus and led the way in developing what is now a large part of the chemical industry.
The simplest standard distillation apparatus is commonly known as a pot still, consisting of a single heated chamber and a vessel to collect purified alcohol. A pot still incorporates only one condensation, whereas other types of distillation equipment have multiple stages which result in higher purification of the more volatile component (alcohol). Pot still distillation gives an incomplete separation, but this can be desirable for the flavor of some distilled beverages.
If a purer distillate is desired, a reflux still is the most common solution. Reflux stills incorporate a fractionating column, commonly created by filling copper vessels with glass beads to maximize available surface area. As alcohol boils, condenses, and reboils through the column, the effective number of distillations greatly increases. Vodka and rum are both distilled by this method, then diluted to concentrations appropriate for human consumption.
Alcoholic products from home distilleries is common throughout the world, but is sometimes in violation of local statutes. The product of illegal stills in the United States is commonly referred to as moonshine.