
Photograph taken in 1826
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 generally considered to be sequences of photographs.
History
Main articles: History of photography
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.
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.
The advent of the
microcomputer and
digital photography has led to the rise of
digital prints. These prints are created from stored
graphic formats such as
JPEG,
TIFF, and
RAW. The types of printers used include
inkjet printers,
dye-sublimation printer,
laser printers, and
thermal printers. The process that use inkjet printers are sometimes given the coined name "
Giclée".
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.
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.
See also
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Digital photography
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Largest photographs in the world
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Pseudo-photograph
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Photograph stability
References