Making long-lasting images by chemically or electronically capturing light using a light-sensitive material, such as photographic film or an image sensor, is the science, practice, and art of photography. In addition to its obvious uses in the arts, film and video production, leisure activities, hobbies, and mass communication, it is also used in many other fields, such as manufacturing (like photolithography) and business.
The light reflected or emitted from objects is typically focused using a lens to create a real image on the light-sensitive surface inside a camera during a timed exposure. An electrical charge is generated at each pixel of an electronic image sensor, which is then processed electronically and stored in a digital image file for later display or processing. Photographic emulsion produces an invisible latent image that, depending on the use of the photographic material and the processing technique, is later chemically "developed" into a visible image, either negative or positive. Traditionally, a negative image on film is used to make a positive image, or print, on the base of the paper. This is done with an enlarger or contact printing.
The word "photography" was created from the Greek roots (phtós), the genitive of (PHS), "light," and (graphé), "representation using lines" or "drawing," together meaning "drawing with light."
The same new term may have been independently created by several people from these roots. French painter and inventor Hércules Florence, who resided in Campinas, Brazil, used the word photography in private notes that a Brazilian historian believes were written in 1834. Although widely reported, this claim is still not widely accepted internationally. After Boris Kossoy's research in 1980, the word's original use by Florence became widely known.
"The German newspaper Vossische Zeitung published an article titled Photographie on February 25, 1839. It discussed several priority claims, particularly Henry Fox Talbot's, about Daguerre's invention claim. The word first appears in print in the article, according to records. It was inscribed "J.M." and was possibly the work of Berlin astronomer Johann von Maedler. Independent of Talbot, the term is also credited to astronomer John Herschel as having been created in 1839."
The three pioneers of photography, Nicéphore Niépce, Henry Fox Talbot, and Louis Daguerre, referred to their processes as "heliography," "photogenic drawing," "Talbotype," and "Daguerreotype," respectively (Daguerre).
The development of photography came about as a result of several technical advancements related to seeing and capturing images. The camera obscura, or "dark chamber" in Latin, which produces an image of a scene, was first discovered in prehistoric China. In the fifth and fourth centuries BCE, the Greek mathematicians Aristotle and Euclid each independently described a camera obscura. Anthemius of Tralles, a Byzantine mathematician, did experiments with an early version of a camera obscura in the sixth century CE.
"In addition to the first true pinhole camera, the Arab physicist Ibn al-Haytham (Alhazen) (965–1040) also created a camera obscura. Ibn al-Wahhab Haytham is credited with the creation of the camera. Ibn al-Haytham was the first to use a screen in a dark room to project an image from one side of a hole in the surface onto a screen on the other side. While the effects of a single light passing through a pinhole had been described earlier, Ibn al-Haytham provided the first accurate analysis of the camera obscura, including the first geometrical and quantitative descriptions of the phenomenon. He also performed the earliest afterimage experiments and understood the relationship between the pinhole and the focal point, laying the groundwork for the development of photography in the 19th century."
"Natural camera Obscura," which is created by dark caves on the edge of a sunny valley, is mentioned by Leonardo da Vinci. A pinhole camera will use a hole in the cave wall to project an image that is laterally reversed and upside down onto a piece of paper. The camera obscura, which provides the optical color rendering that predominates Western art, was used by Renaissance painters. "It is a box with a tiny hole cut out of one side that lets certain light rays pass through, projecting an upside-down image onto a viewing screen or piece of paper."
The development of methods to record and preserve the image created by the camera obscura was then the primary focus of photography. Silver nitrate and silver chloride were discovered by Georg Fabricius (1516–1571) and Albertus Magnus (1193–1280), respectively. Crude photographs can also be made using the methods in Ibn al-Haytham's Optics and materials from the Middle Ages.
In 1566, Daniele Barbaro wrote about a diaphragm. In 1694, Wilhelm Homberg explained how some chemicals became darker when exposed to light (the photochemical effect). Giphantie, a work of fiction written in 1760 by Tiphaigne de la Roche of France, described a process that could be interpreted as photography.
Thomas Wedgwood, a British inventor, made the first known attempt to use a light-sensitive substance to capture an image in a camera obscura around the year 1800. He used white leather that had been treated with silver nitrate or paper. However, it was noted in 1802 that "the images formed using a camera obscura have been found too faint to produce, in any reasonable time, an effect upon the nitrate of silver." This was even though he was successful in capturing the shadows of objects placed on surfaces in direct sunlight and even making shadow copies of paintings on glass. Eventually, the shadowy images turned completely black.
The French inventor Nicéphore Niépce created the first permanent photoetching in 1822, but an attempt to make prints from it later resulted in its destruction. In 1825, Niépce achieved success once more. The earliest still-existing example of natural photography, View from the Window at Le Gras, was created by him in 1826. (i.e., of the image of a real-world scene, as formed in a camera obscura by a lens).
Niépce sought to greatly enhance his bitumen process or replace it with a more practical one because his camera photographs required an incredibly long exposure (at least eight hours and probably several days). He replaced the bitumen with a more light-sensitive resin and developed post-exposure processing techniques in collaboration with Louis Daguerre, but hours of exposure in the camera were still necessary. The partners decided on complete secrecy in anticipation of future commercial exploitation.
After Niépce died in 1833, Daguerre focused his research on the light-sensitive silver halides, which Niépce had previously given up on after failing to make the images he captured with them light-fast and permanent. Daguerre's work culminated in the invention of the daguerreotype method. In 1837, the necessary components—a silver-plated surface that had been developed by mercury vapor, sensitized by iodine vapor, and "fixed" with hot, saturated salt water—were in place. Instead of hours, the necessary exposure time was calculated in minutes. When Daguerre photographed a view of a Parisian street in 1838, one man having his boots polished stood still enough for the several-minute exposure to be visible, in contrast to the other pedestrian and horse-drawn traffic on the busy boulevard that appears deserted. On January 7, 1839, Daguerre's process was publicly revealed but without any further information. An international sensation was caused by the news. Soon after, France agreed to give Daguerre a pension in exchange for the right to declare his invention France's gift to the world, which was done on August 19, 1839, when the full set of operating instructions was revealed. The first surviving photographic self-portrait dates from the same year and is credited to American photographer Robert Cornelius.
Hercules Florence is said to have begun developing a silver-salt-based paper process in Brazil in 1832 and later gave it the name Photographie.
While this was going on, William Fox Talbot, a British inventor, had been working behind the scenes since 1834 to create simple but reasonably light-fast silver images on paper. After learning about Daguerre's invention in January 1839, Talbot made his previously unpublished technique public and began to refine it. Talbot's paper-based photography initially required lengthy exposures in the camera, similar to other pre-daguerreotype processes. However, in 1840, he invented the calotype process, which utilized the chemical development of a latent image to significantly reduce the exposure needed and compete with the daguerreotype. Daguerreotypes could only be duplicated by rephotographing them with a camera, whereas Talbot's process, in both its original and calotype forms, produced a translucent negative that could be used to print multiple positive copies. This is the foundation of most modern chemical photography up to the present day. The oldest camera negative in existence might be Talbot's well-known tiny paper negative of the Oriel window in Lacock Abbey, one of many camera images he took in the summer of 1835.
Hippolyte Bayard said that he invented photography in France before Daguerre or Talbot and that he came up with his way to make direct positive paper prints.
John Herschel, a British chemist, made numerous contributions to the emerging field. He created the cyanotype method, also known as the "blueprint." He coined the terms "photography," "negative," and "positive" first. In 1839, he told Talbot (and, indirectly, Daguerre) that sodium thiosulfate could be used to "fix" silver-halide-based photographs and make them completely light-fast. He discovered in 1819 that sodium thiosulfate was a solvent for silver halides. In late 1839, he created the first glass negative.
Frederick Scott Archer published a description of his wet plate collodion technique in The Chemist's March 1851 issue. Up until the introduction of the gelatin dry plate in the 1870s, it was the most widely used photographic medium. The Ambrotype, a positive image on the glass; the Ferrotype or Tintype, a positive image on metal; and the glass negative, which was used to create positive prints on albumen or salted paper, are the three subsets of the collodion process.
Throughout the rest of the 19th century, significant improvements were made in photographic glass plates and printing. Gabriel Lippmann developed a method for creating natural-color photographs in 1891 that was based on the optical phenomenon of light wave interference. In 1908, he won the Nobel Prize in Physics for an important and elegantly scientific idea that didn't work out in the real world.
Most early camera photography was done on glass plates between the late 1850s and the 1890s when the flexible plastic film became more widely available. Even though early films were less expensive and had significantly lower optical quality than their glass plate equivalents, and they weren't made available in the large formats that most professional photographers preferred until the late 1910s, the new medium did not completely replace the old, even though it greatly increased amateur photography's popularity. Due to the better dimensional stability of glass, plates were still used in science until the 1990s for things like astrophotography. In the specialized field of laser holography, they are still used in the 21st century.
In 1876, Hurter and Driffield started conducting groundbreaking research on the light sensitivity of photographic emulsions. Their efforts made it possible to create the first quantitative gauge of film speed.
George Eastman, the company's founder, introduced the first flexible photographic roll film in 1885, but this first "film" was a coating on a paper base. The image-bearing layer was removed from the paper as part of the processing and transferred to a gelatin support that had hardened. In 1889, the first clear roll of plastic film was made out of nitrate film, which was a very flammable nitrocellulose compound.
Despite being introduced by Kodak in 1908, cellulose acetate, or "safety film," initially found only a few specialized uses as a substitute for hazardous nitrate film, which had the advantages of being significantly more durable, slightly more transparent, and less expensive. While safety film was always used for 16 mm and 8 mm home movies, the transition to X-ray film wasn't finished until 1933, and nitrate film remained the norm for 35 mm theatrical motion pictures until it was finally phased out in 1951.
Up until the early 21st century, the film remained the most popular type of photography. However, developments in digital photography drew customers to digital formats. Even though digital photography now outnumbers film in popularity, both amateurs and professionals still use film. The unique "look" of film-based photographs in comparison to digital images is probably the result of several factors, including (1) spectral and tonal sensitivity differences (an S-shaped density-to-exposure (H&D) curve with film vs. a linear response curve for digital CCD sensors), (2) resolution, and (3) continuity of tone.
All photography was initially monochrome, or black and white. Due to its lower cost, chemical stability, and "classic" appearance, black-and-white photography remained popular for many years after the color film became widely accessible. Black-and-white photography is characterized by the tones and contrast between light and dark areas. Depending on the process, monochromatic images may contain shades of a single color rather than just pure blacks, whites, and grayscale shades in between. For instance, the cyanotype process creates an image with blue tones. The albumen print method, which was made known to the public in 1847, creates brownish tones.
Since well-processed silver-halide-based materials have long been known to have established archival permanence, many photographers still create some monochrome images. Some full-color digital images are converted to black and white using a variety of processing methods, and some producers of digital cameras make models that only capture monochrome images. Certain color photographs that are unsatisfactory in their original form can be saved by monochrome printing or electronic display; occasionally, they are found to be more effective when presented as black-and-white or single-color-toned images. Despite the long-standing dominance of color photography, monochrome images are still created, primarily for artistic purposes. Almost all digital cameras have a monochrome setting, and almost all image editing programs allow you to combine or remove specific RGB color channels to create a monochrome image from a color photo.
Using the three-color separation principle, which Scottish physicist James Clerk Maxwell first published in 1855, the first permanent color photograph was created in 1861. Maxwell's concept, which is essentially the basis of all practical color processes, involved taking three distinct black-and-white photos using red, green, and blue filters. As a result, the photographer has access to the three fundamental channels needed to recreate a color image. An additive method of color reproduction could be used to project transparent prints of the images through comparable color filters and superimpose them on the projection screen. Louis Ducos du Hauron developed a subtractive technique for color reproduction in the late 1860s that involved superimposing carbon prints of the three images made in their complementary colors to create a color print on paper.
Sergei Mikhailovich Prokudin-Gorskii, a Russian photographer, made extensive use of this color separation technique. He used a specialized camera to sequentially expose the three color-filtered images on various regions of an oblong plate. His exposures weren't simultaneous, so moving objects appeared as brightly colored ghosts in the projected or printed images or as unsteady subjects with color "fringes" when they were not.
Early photographic materials were only moderately sensitive to green, barely sensitive to red, and mostly insensitive to blue, which made the implementation of color photography difficult. "Improved color sensitizers and ongoing improvements in the overall sensitivity of emulsions steadily cut the once prohibitively long exposure times needed for color, bringing it ever closer to commercial viability," writes photochemist Hermann Vogel of the dye sensitization process he discovered in 1873.
The Lumière brothers introduced autochrome, the first color process that was successfully used commercially, in 1907. The three colors could be captured as adjacent microscopic image fragments on autochrome plates thanks to a mosaic color filter layer made of colored potato starch grains. The starch grains served to illuminate each fragment with the proper color after an Autochrome plate had been reverse-processed to create a positive transparency, and the tiny colored points blended in the eye, synthesizing the color of the subject by the additive method. Between the 1890s and the 1950s, a variety of additive color screen plates and films were sold, including autochrome plates.
In 1935, Kodak released Kodachrome, the first contemporary "integral tri-pack" (or "mono pack") color film. In a multi-layer emulsion, the three color components were captured. The red-dominated portion of the spectrum was recorded by one layer, the green portion was captured by another, and the blue portion was captured by a third layer. Without special film processing, the result would just be three black-and-white images superimposed, but during a difficult processing step, color couplers were added to create complementary cyan, magenta, and yellow dye images in those layers.
Agfacolor Neu, which has a comparable structure, was first released in 1936. In contrast to Kodachrome, Agfacolor Neu's color couplers were built into the emulsion layers during production, greatly simplifying the processing. The color film most similar to Agfa's is still readily available today and uses the same multi-layer emulsion and principles.
In 1963, Polaroid came out with an instant color film that, when used in a special camera, made a finished color print just a few seconds after the photo was taken.