History of photography
The history of photography has roots in remote antiquity with the discovery of two critical principles, that of the camera obscura image projection and the fact that some substances are visibly altered by exposure to light, as discovered by observation. Apart from a very uncertain process used on the Turin Shroud there are no artifacts or descriptions that indicate that anyone even imagined capturing images with light sensitive materials before the 18th century. Around 1717 Johann Heinrich Schulze captured cut-out letters on a bottle of a light-sensitive slurry, but he apparently never thought of making the results durable. Around 1800 Thomas Wedgwood made the first reliably documented, although unsuccessful attempt at capturing camera images in permanent form. His experiments did produce detailed photograms, but Wedgwood and his associate Humphry Davy found no way to fix these images.
In the mid-1820s, Nicéphore Niépce first managed to fix an image that was captured with a camera, but at least eight hours or even several days of exposure in the camera were required and the earliest results were very crude. Niépce’s associate Louis Daguerre went on to develop the daguerreotype process, the first publicly announced and commercially viable photographic process. The daguerreotype required only minutes of exposure in the camera, and produced clear, finely detailed results. The details were introduced as a gift to the world in 1839, a date generally accepted as the birth year of practical photography. The metal-based daguerreotype process soon had some competition from the paper-based calotype negative and salt print processes invented by William Henry Fox Talbot. Subsequent innovations made photography easier and more versatile. New materials reduced the required camera exposure time from minutes to seconds, and eventually to a small fraction of a second; new photographic media were more economical, sensitive or convenient, including roll films for casual use by amateurs. In the mid-20th century, developments made it possible for amateurs to take pictures in natural color as well as in black-and-white.
The commercial introduction of computer-based electronic digital cameras in the 1990s soon revolutionized photography. During the first decade of the 21st century, traditional film-based photochemical methods were increasingly marginalized as the practical advantages of the new technology became widely appreciated and the image quality of moderately priced digital cameras was continually improved. Especially since cameras became a standard feature on smartphones, taking pictures (and instantly publishing them online) has become an ubiquitous everyday practice around the world.
The coining of the word “photography” is usually attributed to Sir John Herschel in 1839. It is based on the Greek φῶς (phōs), (genitive: phōtós) meaning “light”, and γραφή (graphê), meaning “drawing, writing”, together meaning “drawing with light”.
Early history of the camera
Before 1700: Turin Shroud + light sensitive materials
The notion that light can affect various substances – for instance the suntanning of skin or fading of textile – must have been around since very early times. Ideas of fixing the image seen in mirrors or other ways of creating images automatically may also have been in people’s mind long before anything like photography was developed. However, there seem to be no historical records of any ideas even remotely resembling photography before 1725, despite early knowledge of light-sensitive materials and the camera obscura.
Albertus Magnus (1193/1206–80) discovered silver nitrate and noted that it could blacken skin. Silver nitrate would later be used as a light sensitive material in the photographic emulsion on photographic glass plates and film.
Georg Fabricius (1516–71) discovered silver chloride, later used to make photographic paper.
In 1614 Angelo Sala wrote in his paper Septem Planetarum terrestrium Spagirica recensio: “When you expose powdered silver nitrate to sunlight, it turns black as ink”. He also noted that paper wrapped around silver nitrate for a year had turned black.
Wilhelm Homberg described how light darkened some chemicals (photochemical effect) in 1694.
1816 to 1833: Niépce’s earliest fixed images
In 1816 Nicéphore Niépce, using paper coated with silver chloride, succeeded in photographing the images formed in a small camera, but the photographs were negatives, darkest where the camera image was lightest and vice versa, and they were not permanent in the sense of being reasonably light-fast; like earlier experimenters, Niépce could find no way to prevent the coating from darkening all over when it was exposed to light for viewing. Disenchanted with silver salts, he turned his attention to light-sensitive organic substances.
The oldest surviving photograph of the image formed in a camera was created by Niépce in 1826 or 1827,It was made on a polished sheet of pewter and the light-sensitive substance was a thin coating of bitumen, a naturally occurring petroleum tar, which was dissolved in lavender oil, applied to the surface of the pewter and allowed to dry before use.After a very long exposure in the
camera (traditionally said to be eight hours, but now believed to be several days), the bitumen was sufficiently hardened in proportion to its exposure to light that the unhardened part could be removed with a solvent, leaving a positive image with the light areas represented by hardened bitumen and the dark areas by bare pewter. To see the image plainly, the plate had to be lit and viewed in such a way that the bare metal appeared dark and the bitumen relatively light.
In partnership, Niépce in Chalon-sur-Saône and Louis Daguerre in Paris refined the bitumen process, substituting a more sensitive resin and a very different post-exposure treatment that yielded higher-quality and more easily viewed images. Exposure times in the camera, although substantially reduced, were still measured in hours.
1830 to 1840: early monochrome processes
Niépce died suddenly in 1833, leaving his notes to Daguerre. More interested in silver-based processes than Niépce had been, Daguerre experimented with photographing camera images directly onto a mirror-like silver-surfaced plate that had been fumed with iodine vapor, which reacted with the silver to form a coating of silver iodide. As with the bitumen process, the result appeared as a positive when it was suitably lit and viewed. Exposure times were still impractically long until Daguerre made the pivotal discovery that an invisibly slight or “latent” image produced on such a plate by a much shorter exposure could be “developed” to full visibility by mercury fumes. This brought the required exposure time down to a few minutes under optimum conditions. A strong hot solution of common salt served to stabilize or fix the image by removing the remaining silver iodide. On 7 January 1839, this first complete practical photographic process was announced at a meeting of the French Academy of Sciences,and the news quickly spread. At first, all details of the process were withheld and specimens were shown only at Daguerre’s studio, under his close supervision, to Academy members and other distinguished guests. Arrangements were made for the French government to buy the rights in exchange for pensions for Niépce’s son and Daguerre and present the invention to the world (with the exception of Great Britain, where an agent for Daguerre patented it) as a free gift. Complete instructions were made public on 19 August 1839. Known as the Daguerreotype process, it was the most common commercial process until the late 1850s. It was superseded by the collodion process.
After reading early reports of Daguerre’s invention, Henry Fox Talbot, who had succeeded in creating stabilized photographic negatives on paper in 1835, worked on perfecting his own process. In early 1839, he acquired a key improvement, an effective fixer, from his friend John Herschel, a polymath scientist who had previously shown that hyposulfite of soda (commonly called “hypo” and now known formally as sodium thiosulfate) would dissolve silver salts News of this solvent also benefited Daguerre, who soon adopted it as a more efficient alternative to his original hot salt water method.
In 1839, John Herschel made the first glass negative, but his process was difficult to reproduce. Slovene Janez Puhar invented a process for making photographs on glass in 1841; it was recognized on June 17, 1852 in Paris by the Académie Nationale Agricole, Manufacturière et Commerciale. In 1847, Nicephore Niépce’s cousin, the chemist Niépce St. Victor, published his invention of a process for making glass plates with an albumen emulsion; the Langenheim brothers of Philadelphia and John Whipple and William Breed Jones of Boston also invented workable negative-on-glass processes in the mid-1840s.