Science Fair Project Encyclopedia
Photography is the process of making pictures by means of the action of light. It involves recording light patterns, as reflected from objects, onto a sensitive medium through a timed exposure. The process is done through mechanical, chemical or digital devices commonly known as cameras.
The word comes from the Greek words φως phos ("light"), and γραφις graphis ("stylus", "paintbrush") or γραφη graphê, together meaning "drawing with light" or "representation by means of lines", "drawing".
Image forming devices
Most commonly a camera or camera obscura is the image forming device and photographic film or a digital storage card is the recording medium, but other methods are available. For instance, the photocopy or xerography machine forms permanent images but uses the transfer of static electrical charges rather than photographic film, hence the term electrophotography. The rayographs published by Man Ray in 1922 are images produced by the shadows of objects cast on the photographic paper, without the use of a camera. And one can place objects directly on the glass of a scanner to produce pictures electronically.
Photographers control the camera to expose the light recording material (usually film) to light. After processing, this produces an image whose contents are acceptably sharp, bright and composed to achieve the objective of taking the photograph.
The controls include:
- Aperture of the lens
- Duration of exposure (or shutter speed)
- Focal length of the lens (telephoto, macro, wide angle, or zoom)
- Sensitivity of the film
The controls are usually inter-related, for example brightness is aperture multiplied by shutter speed, and varying the focal length of the lens will allow greater control over the depth of field.
Uses of photography
Photography can be classified under imaging technology and has gained the interest of scientists and artists from its inception. Scientists have used its capacity to make accurate recordings, such as Eadweard Muybridge in his study of human and animal locomotion (1887). Artists have been equally interested by this aspect but have also tried to explore other avenues than the photo-mechanical representation of reality, such as the pictorialist movement. Military, police and security forces use photography for surveillance, recognition and data storage.
History of photography
Projecting images onto surfaces has been done for centuries. The camera obscura and the camera lucida were used by artists to trace scenes as early as the 16th century. These early cameras did not fix an image in time; they only projected what was before an opening in the wall of a darkened room onto a surface. In effect, the entire room was turned into a large pinhole camera.
The first photograph is considered to be an image produced in 1825 by the french inventor Nicéphore Niépce on a polished pewter plate covered with a petroleum derivative called bitumen of Judea. It was produced with a camera, and required an eight hour exposure in bright sunshine. However this process turned out to be a dead end and Niépce began experimenting with silver compounds based on a Johann Heinrich Schultz discovery in 1724 that a silver and chalk mixture darkens when exposed to light.
Niépce, in Chalon-sur-Saône, and the artist Jacques Daguerre, in Paris, refined the existing silver process in a joint partnership. In 1833 Niépce died unexpectedly of a stroke, leaving his notes to Daguerre. While he had no scientific background, Daguerre made two pivotal contributions to the process. He discovered that by exposing the silver firstly to iodine vapour, before exposure to light, and then to mercury fumes after the photograph was taken, a latent image could be formed and made visible. By then bathing the plate in a salt bath the image could be fixed. In 1839 Daguerre announced that he had invented a process using silver on a copper plate called the Daguerreotype. A very similar process is still used today for Polaroids®. The French government bought the patent and immediately made it public domain.
Across the English Channel, William Fox Talbot had earlier discovered another means to fix a silver process image but had kept it secret. After reading about Daguerre's invention, Talbot refined his process, so that it might be fast enough to take photographs of people as Daguerre had done, and by 1840 he had invented the calotype process. He coated paper sheets with silver chloride to create an intermediate negative image. Unlike a daguerreotype, a calotype negative could be used to reproduce positive prints, like most chemical cameras do today. Talbot patented this process, which greatly limited its adoption. He spent the rest of his life in lawsuits defending the patent until he gave up on photography all together. But later this process was refined by George Eastman and is today the basic technology used by chemical film cameras. Hippolyte Bayard also developed a method of photography, but delayed announcing it and so was not recognized as its inventor.
Coe, Brian 'The Birth of Photography' Ash & Grant, 1976
The Daguerreotype proved popular as it responded to the demand for portraiture emerging from the middle classes during the Industrial Revolution. This demand, that could not be met in volume and in cost by oil painting, may well have been the push for the development of photography. But still daguerreotypes, while beautiful, were fragile and difficult to copy. A single photograph taken in a portrait studio could cost $1000 in 2005 dollars. Photographers also encouraged chemists to refine the process of making many copies cheaply, which eventually lead them back to Talbot's process. Ultimately, the modern photographic process came about from a series of refinements and improvements in the first 20 years. In 1884 George Eastman developed dry gel on paper, or film, to replace the photographic plate, so that a photographer no longer needed to carry boxes of plates and toxic chemicals around. In July of 1888 Eastman's Kodak camera went on the market with the slogan "You press the button, we do the rest". Now anyone could take a photograph and leave the dangerous portions of the process to others. Photography became available for the mass-market in 1901 with the introduction of a children's camera, the Kodak Brownie and a women's camera that came with a free lipstick. Very little has changed in chemical photography since then, though color film has become the standard, as well as automatic focus and automatic exposure. Digital recording of images is becoming increasingly prevalent, as digital cameras allow instant previews on LCD screens among other benefits, and the definition of top of the range models have become comparable to high quality 35mm film while lower definition models have become affordable. For the enthusiast photographer processing black and white film, little has changed since the introduction of the 35mm film Leica camera in 1925.
Color photography was explored throughout the 1800s. Initial experiments in color could not fix the photograph and prevent the color from fading. The first permanent color photo was taken in 1861 by the physicist James Clerk Maxwell.
One of the early methods of taking color photos was to use three cameras. Each camera would have a color filter in front of the lens. This technique provides the photographer with the three basic channels required to recreate a color image in a darkroom or processing plant.
The first color film, Autochrome, did not reach the market until 1907 and was based on dyed dots of potato starch. The first modern color film, Kodachrome, was introduced in 1935 based on three colored emulsions. Most modern color films, except Kodachrome, are based on technology developed for Agfacolor (as 'Agfacolor Neue') in 1936. Instant color film was introduced by Polaroid in 1963.
Color photography may form images as a positive transparency, intended for use 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 photograpy, owing to the introduction of automated photoprinting equipment.
Main article: digital photography
Traditional photography was a considerable burden for photographers working at remote locations (such as press correspondents) without access to processing facilities. With increased competition from television, there was pressure to deliver their images to newspapers ever faster. Photo-journalists at remote locations would carry a miniature photo lab with them, and some means of transmitting their images down the telephone line. In 1990, Kodak unveiled the DCS 100 , the first commercially available digital camera. Its cost precluded any use other than photojournalism and professional applications, but commercial digital photography was born.
Digital photography uses an electronic sensor such as a charge-coupled device to record the image as a piece of electronic data rather than as chemical changes on film. Some other devices, such as cell phones, now include digital photography features.
In 10 years, digital cameras have become widespread consumer products. Digital cameras now outsell film cameras, and many include features not found in film cameras such as the ability to shoot video and record audio.
Kodak announced in January 2004 that it would no longer produce reloadable 35-millimeter cameras after the end of that year. This was interpreted as a sign of the end of film photography, however Kodak was at that time a minor actor on the reloadable film cameras market. The price of 35mm and APS compact cameras have dropped, probably due to direct competition from digital and the resulting growth of the offer of second-hand film cameras. However, "wet" photography may endure, as dedicated amateurs and skilled artists often prefer the use of traditional and familiar materials and techniques.
Commercial Photography aka Obtaining Photographic Services
The greater commercial photographic world is traditionally broken down to:
- Advertising Photography: photographs done to illustrate a service or product. These images are generally done with an Advertising Agency, Design Firm or with an in-house Corporate design team.
- Editorial Photography: photographs done to illustrate a story or idea within the context of a magazine. These are usually assigned by the magazine.
- Photo-Journalism: this can be considered a subset of Editorial. Photographs done in this context are accepted as a truthful documentation of a news story.
- Portrait & Wedding Photography: photographs done and sold directly to the end user of the images.
- Fine Art Photography: photographs created to fulfill a vision, and reproduced to be sold directly to the end user.
--- The market for photographic services demonstrates the cliché "one picture is worth a thousand words," which has an interesting basis in the history of photography. Magazines and newspapers, companies putting up Web sites, advertising agencies and other groups pay for photography.
Many people take photographs for self-fulfillment or for commercial purposes. Organizations with a budget and a need for photography have several options: they can assign a member of the organization, hire someone, run a public competition, or obtain rights to stock photographs.
Traditionally, the product of photography has been called a photograph. The term photo is a convenient abbreviation. Many people also call them pictures.
In digital photography, the term image has begun to replace photograph. This term is neither more nor less correct than photograph, either in film or digital photography. (The term image is traditional in geometric optics.)
Photography as an art form
During the twentieth century, art & documentary photography became accepted by the English-speaking art world and the gallery system. In the USA, a small handful of curators spent their lives struggling to put it there; Alfred Stieglitz, Edward Steichen and John Szarkowski, and Hugh Edwards.
Yet the aesthetics of photography is a matter that continues to be discussed. Is photography an art - or is it just the mechanical reproduction of an image? If photography is authentically art, what makes a photograph beautiful? Is there a kinship between the beauty of an Atget and a Rembrandt?
Clive Bell in his classic essay "Art" states that only one thing can distinguish art from what is not art: "significant form." Bell wrote: "There must be some one quality without which a work of art cannot exist; possessing which, in the least degree, no work is altogether worthless. What is this quality? What quality is shared by all objects that provoke our aesthetic emotions? What quality is common to Sta. Sophia and the windows at Chartres, Mexican sculpture, a Persian bowl, Chinese carpets, Giotto's frescoes at Padua, and the masterpieces of Poussin, Piero della Francesca, and Cezanne? Only one answer seems possible - significant form. In each, lines and colours combined in a particular way, certain forms and relations of forms, stir our aesthetic emotions." Text of Bell's essay.
Others have since examined if this criterion be applied to photography. This question has been dealt with by the aesthetic realism understanding of beauty. Some of the most important writing on this subject is to be found on the web sites of Len Bernstein , Louis Dienes, Amy Dienes, and David M. Bernstein: photographers and critics. Len Bernstein has described the Aesthetic Realism understanding of photography as an art formin essays which have been publisheed for example in Apogee Photo Magazine and in Photographica World: The Journal of the Photographic Collectors Club of Great Britain.
On his web site he introduces the subject as follows: "When I began to photograph more than 25 years ago, I felt I found a way of expressing myself that met something so deep inside me that I wanted to do it for the rest of my life. Walking with my camera, the city streets seemed transformed - friendlier, more interesting - and I spent hours searching for dramatic situations, trying to capture the right moment. Looking through the viewfinder, what I saw had new value for me, boredom and loneliness seemed to vanish, and I wished I could feel that way all the time. And hoping to learn what made a photograph successful, I avidly studied the history and technique of photography.
"My hopes were met when I first heard this magnificent statement by Eli Siegel, the American critic and founder of the philosophy Aesthetic Realism: 'All beauty is a making one of opposites, and the making one of opposites is what we are going after in ourselves.' This is the criterion for beauty that centuries of artists, philosophers, people in all walks of life, have searched for; the explanation of what makes a photograph good and how our personal questions are the questions of art - dignified and cultural! I've had the thrill of testing it in thousands of instances, from the first known photograph taken by Nicéphore Niépce in 1826-27 to the most modern work of today." For an online exhibition of Bernstein's photographs click here.
Likewise, important articles (referred to above) on photography as an art form, written from the Aesthetic Realism point of view, will be found on the David M. Bernstein web site "What Does a Person Deserve? The Answer Found in a Great Photograph" and the "Dienes & Dienes" web site. See, for example Amy Dienes' "The Self Alone & The Self Going Out; or, Cartier-Bresson's Photo of a Leaping Man"; Louis Dienes' "On a Photograph by Eugene Atget" and his illustrated poem "Black and White," originally composed for his own exhibition of photographs, which begins: "The day black and white got a break..."
The question, "Is photography an art form?" gets us into deepest aesthetics and is a most important question.
An often neglected form of art in photography is that of portrait photography. A portrait is the basic rendering of someone’s likeness. A good portrait photographer, not only wants to capture the true likeness, but also the personality of the individual. The photographer needs to be proficient not only in the workings and setting of the camera, but also needs to understand form and lighting. Great lighting and positioning can make someone appear at their best form if used correctly. Lighting and camera placement can also aid in correcting defects such as shortening a nose, making someone appear slimmer, etc. In this form of art, portrait photography takes on many roles, and can help create various moods that the individual is seeking.
Tom Ang, Dictionary of Photography and Digital Imaging, The Essential Reference for the Modern Photographer (Argentum 2001)
Basic topics in photography
- Film format
- Color temperature
- Photographic printing
- Photographic processes
- Movie projector
- Slide projector
- Stock photography
- angle of view
- depth of field
- double exposure
- film developing
- macro photography
- panoramic photography
- Perspective distortion (caused by camera to subject distance)
- push printing
- red eye effect
- rollout photography
- rule of thirds
- film scanning
- shutter speed
- Zone System
- still camera
- pinhole camera
- toy camera
- photographic lens
- photographic film
- film formats
- dry box
- zone plate
- Camera obscura
- Diana camera
- Gelatin-silver process
- Night photography
- Kirlian photography
- Street photography
- Stock photography
- Depth of Field Calculators
- dpreview.com digital camera reviews
- PhotoPermit.Org discussion on copyright law for photographers
- The Luminous Landscape - photography techniques and camera reviews
- Photography Composition Articles
- Ken Rockwell Photography Photography information and careful equipment reviews--the lens reviews are especially useful
- David Kachel's Front Door Articles on the zone system and photographic printing, including novel contrast control processes
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