Calotype or talbotype is an early photographic process introduced in 1841 by William Henry Fox Talbot, καλός (kalos), "beautiful", and τύπος (tupos), "impression".using paper coated with silver iodide. The term calotype comes from the Greek
Paper is a thin material produced by pressing together moist fibres of cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets. It is a versatile material with many uses, including writing, printing, packaging, cleaning, decorating, and a number of industrial and construction processes. Papers are essential in legal or non-legal documentation.
Silver iodide is an inorganic compound with the formula AgI. The compound is a bright yellow solid, but samples almost always contain impurities of metallic silver that give a gray coloration. The silver contamination arises because AgI is highly photosensitive. This property is exploited in silver-based photography. Silver iodide is also used as an antiseptic and in cloud seeding.
Greek is an independent branch of the Indo-European family of languages, native to Greece, Cyprus and other parts of the Eastern Mediterranean and the Black Sea. It has the longest documented history of any living Indo-European language, spanning more than 3000 years of written records. Its writing system has been the Greek alphabet for the major part of its history; other systems, such as Linear B and the Cypriot syllabary, were used previously. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic, and many other writing systems.
Talbot made his first successful camera photographs in 1835 using paper sensitised with silver chloride, which darkened in proportion to its exposure to light. This early "photogenic drawing" process was a printing-out process, i.e., the paper had to be exposed in the camera until the image was fully visible. A very long exposure—typically an hour or more—was required to produce an acceptable negative.
Silver chloride is a chemical compound with the chemical formula AgCl. This white crystalline solid is well known for its low solubility in water (this behavior being reminiscent of the chlorides of Tl+ and Pb2+). Upon illumination or heating, silver chloride converts to silver (and chlorine), which is signaled by grey to black or purplish coloration to some samples. AgCl occurs naturally as a mineral chlorargyrite.
In photography, a negative is an image, usually on a strip or sheet of transparent plastic film, in which the lightest areas of the photographed subject appear darkest and the darkest areas appear lightest. This reversed order occurs because the extremely light-sensitive chemicals a camera film must use to capture an image quickly enough for ordinary picture-taking are darkened, rather than bleached, by exposure to light and subsequent photographic processing.
In late 1840, Talbot worked out a very different developing-out process (a concept pioneered by the daguerreotype process introduced in 1839), in which only an extremely faint or completely invisible latent image had to be produced in the camera, which could be done in a minute or two if the subject was in bright sunlight. The paper, shielded from further exposure to daylight, was then removed from the camera and the latent image was chemically developed into a fully visible image. This major improvement was introduced to the public as the calotype or talbotype process in 1841.
The daguerreotype process, or daguerreotypy, was the first publicly available photographic process, and for nearly twenty years it was the one most commonly used.
A latent image is an invisible image produced by the exposure to light of a photosensitive material such as photographic film. When photographic film is developed, the area that was exposed darkens and forms a visible image. In the early days of photography, the nature of the invisible change in the silver halide crystals of the film's emulsion coating was unknown, so the image was said to be "latent" until the film was treated with photographic developer.
Photographic processing or development is the chemical means by which photographic film or paper is treated after photographic exposure to produce a negative or positive image. Photographic processing transforms the latent image into a visible image, makes this permanent and renders it insensitive to light.
The light-sensitive silver halide in calotype paper was silver iodide, created by the reaction of silver nitrate with potassium iodide. First, "iodised paper" was made by brushing one side of a sheet of high-quality writing paper with a solution of silver nitrate, drying it, dipping it in a solution of potassium iodide, then drying it again. At this stage, the balance of the chemicals was such that the paper was practically insensitive to light and could be stored indefinitely. When wanted for use, the side initially brushed with silver nitrate was now brushed with a "gallo-nitrate of silver" solution consisting of silver nitrate, acetic acid and gallic acid, then lightly blotted and exposed in the camera. Development was effected by brushing on more of the "gallo-nitrate of silver" solution while gently warming the paper. When development was complete, the calotype was rinsed, blotted, then either stabilized by washing it in a solution of potassium bromide, which converted the remaining silver iodide into silver bromide in a condition such that it would only slightly discolour when exposed to light, or "fixed" in a hot solution of sodium thiosulphate, then known as hyposulphite of soda and commonly called "hypo", which dissolved the silver iodide and allowed it to be entirely washed out, leaving only the silver particles of the developed image and making the calotype completely insensitive to light.
A silver halide is one of the chemical compounds that can form between the element silver and one of the halogens. In particular, bromine, chlorine, iodine and fluorine may each combine with silver to produce silver bromide (AgBr), silver chloride (AgCl), silver iodide (AgI), and three forms of silver fluoride, respectively.
Silver nitrate is an inorganic compound with chemical formula AgNO
3. This compound is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called lunar caustic because silver was called luna by the ancient alchemists, who believed that silver was associated with the moon.
Potassium iodide is a chemical compound, medication, and dietary supplement. As a medication it is used to treat hyperthyroidism, in radiation emergencies, and to protect the thyroid gland when certain types of radiopharmaceuticals are used. In the developing world it is also used to treat skin sporotrichosis and phycomycosis. As a supplement it is used in those who have low intake of iodine in the diet. It is given by mouth.
The calotype process produced a translucent original negative image from which multiple positives could be made by simple contact printing. This gave it an important advantage over the daguerreotype process, which produced an opaque original positive that could only be duplicated by copying it with a camera.
Positive-negative film is instant photographic film that generates both a positive print and a negative from a single exposure on a single medium.
A contact print is a photographic image produced from film; sometimes from a film negative, and sometimes from a film positive or paper negative. In a darkroom an exposed and developed piece of photographic film or paper is placed emulsion side down, in contact with a piece of photographic paper, light is briefly shone through the negative or paper and then the paper is developed to reveal the final print.
Although calotype paper could be used to make positive prints from calotype negatives, Talbot's earlier silver chloride paper, commonly called salted paper, was normally used for that purpose. It was simpler and less expensive, and Talbot himself considered the appearance of salted paper prints to be more attractive. The longer exposure required to make a salted print was at worst a minor inconvenience when making a contact print by sunlight. Calotype negatives were often impregnated with wax to improve their transparency and make the grain of the paper less conspicuous in the prints.
Talbot is sometimes erroneously credited[ by whom? ] with introducing the principle of latent image development. The bitumen process used in private experiments by Nicéphore Niépce during the 1820s involved the chemical development of a latent image, as did the widely used daguerreotype process introduced to the public by Niépce's partner and successor Louis Daguerre in 1839. Talbot was, however, the first to apply it to a paper-based process and to a negative-positive process, thereby pioneering the various developed-out negative-positive processes which have dominated non-electronic photography up to the present.
Joseph Nicéphore Niépce, commonly known or referred to simply as Nicéphore Niépce, was a French inventor, usually credited as the inventor of photography and a pioneer in that field. Niépce developed heliography, a technique he used to create the world's oldest surviving product of a photographic process: a print made from a photoengraved printing plate in 1825. In 1826 or 1827, he used a primitive camera to produce the oldest surviving photograph of a real-world scene. Among Niépce's other inventions was the Pyréolophore, the world's first internal combustion engine, which he conceived, created, and developed with his older brother Claude.
Louis-Jacques-Mandé Daguerre, better known as Louis Daguerre, was a French artist and photographer, recognized for his invention of the daguerreotype process of photography. He became known as one of the fathers of photography. Though he is most famous for his contributions to photography, he was also an accomplished painter and a developer of the diorama theatre.
Despite their flexibility and the ease with which they could be made, calotypes did not displace the daguerreotype.In part, this was the result of Talbot having patented his processes in England and beyond. Unlike Talbot, Daguerre who had been granted a stipend by the French state in exchange for making his process publicly available, did not patent his invention. In Scotland, where the English patent law was not applicable at the time, members of the Edinburgh Calotype Club and other Scottish early photographers successfully adopted the paper-negative photo technology. In England, the Calotype Society was organized in London around 1847 attracting a dozen enthusiasts. In 1853, after twelve years passed since unveiling of paper-negative photography to the public, Talbot's patent restrictions has been softened.
In addition, the calotype produced a less clear image than the daguerreotype. The use of paper as a negative meant that the texture and fibers of the paper were visible in prints made from it, leading to an image that was slightly grainy or fuzzy compared to daguerreotypes, which were usually sharp and clear.Nevertheless, calotypes—and the salted paper prints that were made from them—remained popular in the United Kingdom and on the European continent outside France in the 1850s, especially among the amateur calotypists, who prized the aesthetics of calotypes and also wanted to differentiate from commercial photographers, until the collodion process enabled both to make glass negatives combining the sharpness of a daguerreotype with the replicability of a calotype later in the nineteenth century.
Photography is the art, application and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed in many fields of science, manufacturing, and business, as well as its more direct uses for art, film and video production, recreational purposes, hobby, and mass communication.
The following list comprises significant milestones in the development of photography technology.
William Henry Fox Talbot FRS FRSE FRAS was an English scientist, inventor and photography pioneer who invented the salted paper and calotype processes, precursors to photographic processes of the later 19th and 20th centuries. His work, in the 1840s on photomechanical reproduction, led to the creation of the photoglyphic engraving process, the precursor to photogravure. He was the holder of a controversial patent which affected the early development of commercial photography in Britain. He was also a noted photographer who contributed to the development of photography as an artistic medium. He published The Pencil of Nature (1844–46), which was illustrated with original salted paper prints from his calotype negatives, and made some important early photographs of Oxford, Paris, Reading, and York.
The collodion process is an early photographic process.
The albumen print, also called albumen silver print, was published in January 1847 by Louis Désiré Blanquart-Evrard, and was the first commercially exploitable method of producing a photographic print on a paper base from a negative. It used the albumen found in egg whites to bind the photographic chemicals to the paper and became the dominant form of photographic positives from 1855 to the start of the 20th century, with a peak in the 1860-90 period. During the mid-19th century, the carte de visite became one of the more popular uses of the albumen method. In the 19th century, E. & H. T. Anthony & Company were the largest makers and distributors of the Albumen photographic prints and paper in the United States.
The ambrotype or amphitype, also known as a collodion positive in the UK, is a positive photograph on glass made by a variant of the wet plate collodion process. Like a print on paper, it is viewed by reflected light. Like the daguerreotype, which it replaced, and like the prints produced by a Polaroid camera, each is a unique original that could only be duplicated by using a camera to copy it.
A tintype, also known as a melainotype or ferrotype, is a photograph made by creating a direct positive on a thin sheet of metal coated with a dark lacquer or enamel and used as the support for the photographic emulsion. Tintypes enjoyed their widest use during the 1860s and 1870s, but lesser use of the medium persisted into the early 20th century and it has been revived as a novelty and fine art form in the 21st.
The history of photography began in remote antiquity with the discovery of two critical principles: camera obscura image projection and the observation that some substances are visibly altered by exposure to light. Apart from a possibly photographic but unrecognized process used on the Turin Shroud there are no artifacts or descriptions that indicate any attempt to capture images with light sensitive materials prior to 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.
John Adams Whipple was an American inventor and early photographer. He was the first in the United States to manufacture the chemicals used for daguerreotypes; he pioneered astronomical and night photography; he was a prize-winner for his extraordinary early photographs of the moon; and he was the first to produce images of stars other than the sun (the star Vega and the Mizar-Alcor stellar sextuple system, which was thought to be a double star until 2009.
A chromogenic print, also known as a silver halide print, or a dye coupler print, is a photographic print made from a color negative, transparency, or digital image, and developed using a chromogenic process. They are composed of three layers of gelatin, each containing an emulsion of silver halide, which is used as a light-sensitive material, and a different dye coupler of subtractive color which together, when developed, form a full-color image.
Louis Désiré Blanquart-Evrard was a French inventor, photographer and photo publisher. Being a cloth merchant by trade, in the 1840s he developed interest in photography and focused on technical and economical issues of mass production of photo prints.
The following outline is provided as an overview of and topical guide to photography:
The salt print was the dominant paper-based photographic process for producing positive prints from 1839 until approximately 1860.
Paper texture effects in calotype photography limit the ability of this early process to record low contrast details and textures. A calotype is a photographic negative produced on uncoated paper. An important feature is that a relatively short exposure in a camera produces a latent image that is subsequently made visible by development. Then positive images for viewing are obtained by contact printing. This technique was in use principally from 1840 into the 1850s, when it was displaced by photography on glass. Skilled photographers were able to achieve dramatic results with the calotype process, and the reason for its eclipse may not be evident from viewing reproductions of early work.
Peter Wickens Fry was a pioneering English amateur photographer, although professionally he was a London solicitor. In the early 1850s, Fry worked with Frederick Scott Archer, assisting him in the early experiments of the wet collodion process. He was also active in helping Roger Fenton to set up the Royal Photographic Society in 1853. Several of his photographs are in the Victoria and Albert Museum in London.
Samuel Buckle was an early English photographer.
John McCosh or John MacCosh or James McCosh was a Scottish army surgeon who made hobbyist photographs whilst serving in India and Burma. His photographs during the Second Anglo-Sikh War (1848–1849) of people and places associated with the British rule in India, and of the Second Burmese War (1852–1853), count as sufficient grounds, some historians maintain, to recognise him as the first war photographer known by name. McCosh wrote a number of books on medicine and photography as well as books of poetry.
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