posted by hot news on Oct 22
Photography is the result of combining several technical inventions . Long before the first photographs were made, Chinese philosopher Mo Ti described a pinhole camera in the 5th century, Albertus Magnus discovered silver nitrate and Georges Fabricius discovered silver chloride. Daniel Barbaro described a diaphragm in 1568. Wilhelm Homberg described how light darkened some chemicals (photochemical effect) in 1694. The fiction book Giphantie, published in 1760, by French author Tiphaigne de la Roche, described what can be interpreted as photography.
Photography as a usable process goes back to the 1820s with the development of chemical photography. The first visible photograph was an image produced in 1825 by the French inventor Nicéphore Niépce. However, because his photographs took so long to expose, he sought to find a new process. Working with Louis Daguerre, they experimented with silver compounds based on a Johann Heinrich Schultz discovery in 1724 that a silver and chalk mixture darkens when exposed to light. Niépce died in 1833, but Daguerre continued the work, eventually culminating with the development of the daguerreotype in 1837. Daguerre took the original photo of a person in 1839 when, while taking a daguerreotype of a Paris street, a pedestrian stopped for a shoe shine, long enough to be captured by the long exposure (several minutes). Eventually, France agreed to pay Daguerre a pension for his formula, in exchange for his promise to announce his discovery to the world as the gift of France, which he did in 1839.
Meanwhile, Hercules Florence had already developed a very similar process in 1832, naming it Photographie and 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 portraits were made readily available to the masses. By 1840, Talbot had invented the calotype process, which deliveres negative images. John Herschel made many contributions to the new methods. He invented the cyanotype process, now familiar as the “blueprint”. He was the first to use the terms “photography”, “negative” and “positive”. He discovered sodium thiosulphate solution to be a solvent of silver halides in 1819, and informed Talbot and Daguerre of his discovery in 1839 that it could be used to “fix” pictures and make them permanent. He made the first glass negative in late 1839.
In March 1851, Frederick Scott Archer shared his findings in “The Chemist” on the wet plate collodion process. This became the most widely used process between 1852 and the late 1880s when the dry plate was introduced. There are three subsets to the Collodion process; the Ambrotype (positive image on glass), the Ferrotype or Tintype (positive image on metal) and the negative which was printed on Albumen or Salt paper.
Many developments in photographic glass plates and printing were made in through the nineteenth century. In 1884, George Eastman developed the technology of film to replace photographic plates, leading to the technology used by film cameras today.
In 1908 Gabriel Lippmann won the Nobel Laureate in Physics for his way of reproducing colours photographically based on the phenomenon of interference, also known as the Lippmann plate.
Processes
Black and White Images
Pictures originally were monochrome and even after colour film was easily available, the commercial photographer used black and white photographic images and prints in preference.
It is important to note that some monochromatic pictures are not always pure blacks and whites, but also contain other hues depending on the process. The Cyanotype process produces an image of blue and white for example. The albumen process which was used more than 150 years ago had brown tones.
Many photographers continue to produce some black and white images. Some full colour digital images are processed using a variety of techniques to create black and whites, and some cameras have even been produced to exclusively shoot monochrome.
Colour
Colour photography was explored at the beginning in the mid 1800s. Early tests in colour could not fix the photograph and prevent the colour from fading. The first permanent colour photo was taken in 1861 by the physicist James Clerk Maxwell.
Early colour photographs were taken by Prokudin-Gorskii (1915). One of the early methods of taking colour photos was to use three cameras. Each camera would have a colour filter in front of the lens. This process provides the photographer with the three basic channels required to recreate a colour still in a darkroom or processing plant . Russian photographer Sergei Mikhailovich Prokudin-Gorskii developed another technique, with three colour plates taken in quick succession.
A practical application of the process was held back by the very limited colour response of early film, however, in the early 1900s, following the work of photo-chemists such as H. W. Vogel, emulsions with adequate sensitivity to green and red light at last became available.
The first colour plate, Autochrome, invented by the French Lumière brothers, reached the market in 1907. It was based on a ’screen-plate’ filter made of dyed dots of potato starch, and was the only colour film on the market until German Agfa introduced the similar Agfacolor in 1932. In 1935, American Kodak introduced the first modern (‘integrated tri-pack’) colour film which was developed by Polish constructor Jan Szczepanik. It was Kodachrome, based on three coloured emulsions. This was followed in 1936 by Agfa’s Agfacolor Neue. Unlike the Kodachrome tri-pack process, the colour couplers in Agfacolor Neue were integral with the emulsion layers, which greatly simplified the film processing . Most contemporary colour films, except Kodachrome, are based on the Agfacolor Neue technology. Instant colour film was introduced by Polaroid in 1963.
Colour photography may form images as a positive transparency, intended for use in a slide projector or as colour negatives intended for use in creating positive colour prints on specially coated paper. The latter is now the most common form of film (non-digital) colour photography owing to the introduction of automated photo printing equipment.
Full spectrum photography ultraviolet and infrared
Ultraviolet and infrared films have been available for decades and employed in a variety of photographic avenues since the 1960s. New technological developments in digital photography have opened a new direction in full spectrum photography, where careful filtering choices across the ultraviolet, visible and infrared lead to new artistic visions.
Modified digital cameras can display some ultraviolet light and all of the visible and much of the near infrared spectrum. As most digital imaging sensors are sensitive from about 350 nm to 1000 nm. An off-the-shelf digital camera contains an infrared hot mirror filter that blocks most of the infrared and a bit of the ultraviolet that would otherwise be detected by the sensor, narrowing the accepted range from about 400 nm to 700 nm. Replacing a hot mirror or infrared blocking filter with an infrared pass or a wide spectrally transmitting filter allows the camera to detect the wider spectrum light at greater sensitivity. Missing the hot-mirror, the red, green and blue (or cyan, yellow and magenta) coloured micro-filters placed over the sensor elements pass varying amounts of ultraviolet (blue window) and infrared (primarily red, and somewhat lesser the green and blue micro-filters).
Uses of full spectrum photography are for fine art photography, geology, forensics and law enforcement and even some claimed use in ghost hunting.
Digital Photography
The Nikon D1 was the first DSLR to truly compete with and begin to replace, film cameras in the professional photojournalism and sports photography fields and was the start of something very new.
The commercial photographer had quite a challenge on his hands, how to get the picture developed quickly and delivered to the newspapers while out on location, while being in competition with real time television and without the readily available processing facilities.
Press and News photographers at remote locations often carried miniature photo labs and a means of transmitting images through telephone lines. In 1981, Sony unveiled the first public camera to use a charge-coupled device for imaging, eliminating the need for film: the Sony Mavica. While the Mavica saved images to disk, the images were displayed on television and the camera was not fully digital. In 1990, Kodak unveiled the DCS 100, the first commercially available digital camera. Although its high cost precluded uses other than photojournalism and professional photography, commercial digital photography was born.
Digital imaging uses an electronic image sensor to record the image as a set of electronic data rather than as chemical changes on film. The primary difference between digital and chemical photography is that chemical photography resists manipulation because it involves film and photographic paper, while digital imaging is a highly adaptable medium. This difference allows for a degree of image post-processing that is comparatively difficult in film-based photography and permits different communicative potentials and applications.
Digital compact cameras have become widespread public products, outselling film cameras and including new features such as video and audio recording. Kodak announced back in January 2004 that it would no longer sell reloadable 35 mm cameras in western Europe, Canada and the United States after the end of that year. Kodak was at that time a minor player in the reloadable film cameras market. In January 2006, Nikon followed suit and announced that they will stop the production of all but two models of their film cameras: the low-end Nikon FM10, and the high-end Nikon F6. On May 25, 2006, Canon stated that they will stop developing new film SLR cameras. Though most new camera designs are now digital, a new 6×6cm/6×7cm medium format film camera was introduced in 2008 in a co-operation between Fuji and Voigtländer.
According to a study made by Kodak in 2007, 75 percent of professional photographers say they will continue to use film, even though some embrace digital.
A survey held in the U.S. showed that over two thirds of the professional photographer group that compared film images to digital images liked the film results better for some circumstances which included:
- film’s superiority in capturing more information on medium and large format films (48 percent);
- creating a traditional photographic look (48 percent);
- capturing shadow and highlighting details (45 percent);the wide exposure latitude of film (42 percent); and
- archival storage. (38 percent)
Digital capture has raised many ethical concerns because of the ease of manipulating digital photographs in post processing. Many snappers have declared they will not crop their pictures, or are forbidden from combining elements of multiple photos to make “illustrations,” passing them as real photographs. Today’s technology has made picture editing relatively simple for even the novice photographer. However, recent changes of in camera processing allows digital fingerprinting of RAW photos to verify against tampering of digital photos for forensics use.
Camera phones, combined with popular photo sharing web sites, have lead the way to a new kind of social photography. But that is a whole new article.
Author: Peter Davey MA DipM