The collodion process is an early photographic process. The collodion process, mostly synonymous with the "collodion wet plate process", requires the photographic material to be coated, sensitized, exposed, and developed within the span of about fifteen minutes, necessitating a portable darkroom for use in the field. Collodion is normally used in its wet form, but it can also be used in its dry form, at the cost of greatly increased exposure time. The increased exposure time made the dry form unsuitable for the usual portraiture work of most professional photographers of the 19th century. The use of the dry form was mostly confined to landscape photography and other special applications where minutes-long exposure times were tolerable.[1]
This deteriorated dry plate portrait of Theodore Roosevelt is similar to a wet plate image but has substantial differences.
Gustave Le Gray first theorized about the collodion process, publishing a method in 1850 that was "theoretical at best",[2] but Frederick Scott Archer was credited with the invention of the process, which he created in 1848 and published in 1851. During the subsequent decades, many photographers and experimenters refined or varied the process. By the end of the 1860s, it had almost entirely replaced the first-announced photographic process, the daguerreotype.
During the 1870s, the collodion process was largely replaced by gelatin dry plates—glass plates with a photographic emulsion of silver halides suspended in gelatin. Invented by Dr. Richard Leach Maddox in 1871, dry gelatin emulsion was not only more convenient, but it could also be made much more sensitive, greatly reducing exposure times. This marked the beginning of the modern era of photography.
One collodion process, the tintype, was in limited use for casual portraiture by some itinerant and amusement park photographers as late as the 1930s, and the wet plate collodion process was still in use in the printing industry in the 1960s for line and tone work, mostly printed material involving black type against a white background because, in large volumes, it was much cheaper than gelatin film.[citation needed]
21st century
The wet plate collodion process has undergone a revival as a historical technique in the twenty-first century.[3] There are several practicing ambrotypes and tintypes who regularly set up and make images, for example at Civil War re-enactments and arts festivals. Fine art photographers use the process and its handcrafted individuality for gallery showings and personal work. There are several makers of reproduction equipment, and many artists work with collodion around the globe. The process is taught in workshops around the world and several workbooks and manuals are in print. Modern collodion artists include:
A portable photography studio in 19th-century Ireland. The wet collodion process sometimes gave rise to portable darkrooms, as photographic images needed to be developed while the plate was still wet.Animation illustrating the detail found in a wet-collodion photograph taken in Hill End in 1872.
The collodion process produced a negative image on a transparent support (glass). This was an improvement over the calotype process, discovered by Henry Fox Talbot, which relied on paper negatives, and the daguerreotype, which produced a one-of-a-kind positive image and could not be replicated. The collodion process thus combined desirable qualities of the calotype process (enabling the photographer to make a theoretically unlimited number of prints from a single negative) and the daguerreotype (creating a sharpness and clarity that could not be achieved with paper negatives). Collodion printing was typically done on albumen paper.
As collodion is a sticky and transparent medium and can be soaked in a solution of silver nitrate while wet, it is ideal for coating stable surfaces such as glass or metal for photography. When a metal plate is coated with collodion, charged with silver nitrate, exposed, and developed, it produces a direct positive image on the plate, although laterally reversed (left and right would be reversed, like in a mirror). When coated on glass, the image becomes negative and can be reproduced easily on photographic paper. This was a huge advantage over the daguerreotype, which was not directly reproducible. Wet plate/collodion is also a relatively inexpensive process compared to its predecessor, and does not require polishing equipment or the extremely toxic fuming boxes needed for the daguerreotype. With glass as the medium, the cost per image was also far less than special silver-plated copper plates, and more durable than paper negatives. The process was also very fast for the time, requiring only a few seconds to expose an image in daylight, rather than 30 seconds or more for other forms of photography available in the mid-1800s.
Disadvantages
The wet collodion process had a major disadvantage. The entire process, from coating to developing, had to be done before the plate dried. This gave the photographer no more than about 10-15 minutes to complete everything. This made it inconvenient for field use, as it required a portable darkroom. The plate dripped silver nitrate solution, causing stains and potentially explosive build-up of nitrate residue in the camera and plate holders.
The silver nitrate bath was also a source of problems. It gradually became saturated with alcohol, ether, iodide and bromide salts, dust, and various organic matter. It would lose effectiveness, causing plates to mysteriously fail to reproduce an image.
As with all preceding photographic processes, the wet-collodion process was sensitive only to blue and ultraviolet light. Warm colors appear dark, cool colors uniformly light. A sky with clouds is quite difficult to render, as the spectrum of white clouds contains about as much blue as the sky. Lemons and tomatoes appear shiny black, and a blue and white tablecloth appears plain white. Victorian sitters who in collodion photographs look as if they are in mourning might have been wearing bright yellow or pink.[21]
Use
North Sydney and Sydney Harbour, by C Bayliss B Holtermann, 1875, colossal collodion glass-plate negative
Despite its disadvantages, wet plate collodion became enormously popular. It was used for portraiture, landscape work, architectural photography, and art photography.[citation needed] The largest collodion glass plate negatives produced in the nineteenth century were made in Sydney, Australia, in 1875. They were made by the professional photographer Charles Bayliss with the help of a wealthy amateur photographer Bernhard Otto Holtermann, who also funded the project.[22]
Bayliss and Holtermann produced four known glass negatives all of which were taken from Holtermann's purpose-built camera in the tower of his mansion in North Sydney.[23] Two were 160 x 96.5 cm (5.1 ft x 3.08 ft) and formed a panorama of Sydney Harbour from Garden Island to Miller's Point. The other two were 136 x 95 cm (4.4 x 3.1 feet) and were of the Harbour and Garden Island and Longnose Point. Three of the four are now held by the State Library of New South Wales.[24]
The wet plate process is used by a number of artists and experimenters who prefer its aesthetic qualities to those of the more modern gelatin silver process.[citation needed] World Wet Plate Day is staged annually in May for contemporary practitioners.[25]Oskar Barnack Award winning photojournalist and contemporary collodion wet plate artist Charles Mason[26][27] finds an artistic appeal in the uncertainty of the results of a wet plate photograph that cannot be recreated with modern digital photography.[28] Mason says "If you plan it, then it becomes contrived, If you just let it happen, it's the gods helping you out."[29] In 2018 Mason completed an artist-in-residency program with Denali National Park where he produced 24 collodion wet plate images of the park.[30]
Search for a dry collodion process
The extreme inconvenience of exposing wet collodion in the field led to many attempts to develop a dry collodion process, which could be exposed and developed sometime after coating. A large number of methods were tried, though none were ever found to be truly practical and consistent in operation. Well-known scientists such as Joseph Sidebotham, Richard Kennett, Major Russell, and Frederick Charles Luther Wratten attempted but never met with good results.[citation needed]
Typically, methods involved coating or mixing the collodion with a substance that prevented it from drying quickly. As long as the collodion remained at least partially wet, it retained some of its sensitivity. Common processes involved chemicals such as glycerin, magnesium nitrate, tannic acid and albumen. Others involved more unlikely substances, such as tea, coffee, honey, beer, and seemingly unending combinations thereof.[citation needed]
Many methods worked to an extent; they allowed the plate to be exposed for hours, or even days, after coating. They all possessed the chief disadvantage, that they rendered the plate extremely slow. An image could require anywhere from three to ten times more exposure on a dry plate than on a wet plate.[citation needed]
Collodion emulsion
British veteran of the Napoleonic War with his wife, c.1860, hand-tinted ambrotype using the bleached collodion positive process.
In 1864 W. B. Bolton and B. J. Sayce published an idea for a process that would revolutionize photography. They suggested that sensitive silver salts be formed in a liquid collodion, rather than being precipitated, in-situ, on the surface of a plate. A light-sensitive plate could then be prepared by simply flowing this emulsion across the surface of a glass plate; no silver nitrate bath was required.
This idea was soon brought to fruition. First, a printing emulsion was developed using silver chloride. These emulsions were slow, and could not be developed, so they were mostly used for positive printing. Shortly later, silver iodide and silver bromide emulsions were produced. These proved to be significantly faster, and the image could be brought out by development.
The emulsions also had the advantage that they could be washed. In the wet collodion process, silver nitrate reacted with a halide salt; potassium iodide, for example. This resulted in a double replacement reaction. The silver and iodine ions in the solution reacted, forming silver iodide on the collodion film. However, at the same time, potassium nitrate also formed, from the potassium ions in the iodide and the nitrate ions in the silver. This salt could not be removed in the wet process. However, with the emulsion process, it could be washed out after the creation of the emulsion.
The speed of the emulsion process was unremarkable. It was not as fast as the ordinary wet process, but was not nearly as slow as the dry plate processes. Its chief advantage was that each plate behaved the same way. Inconsistencies in the ordinary process were rare.
Phenotype
The phenotype (from Latin pannus = cloth) is a direct positive that, like the tintype, uses collodion emulsion from an underexposed image that is transferred to a dark surface so that transparent (unexposed) areas appear black and weak precipitated silver (highlights) appear brighter in reflected light, on the same principle as the daguerreotype and ambrotype.[31] It was invented in 1852 by French photographer Jean Nicolas Truchelut, a pupil of Louis Daguerre and an itinerant daguerreotypist. Similar images on black waxed linen were displayed at the French Academy of Sciences by Wulff & Co. in 1853.[31]
Various substrates were tried including wood, and Australian photographers Alfred R. Fenton[32] and Frederick H. Coldrey patented a version on black leather in 1857 to create an unbreakable photograph that could be sent by mail.[33] Various practitioners formulated, and some patented, their own recipes with the aim of good adhesion, but a disadvantage of using such supports was that flexing of the surface caused cracking and flaking of the emulsion so few historical examples survive. The process continued to be used until the 1880s but was being gradually displaced by the more durable tintype from the 1860s.[31]
Below is an example of the preparation of a collodion emulsion, from the late 19th century. The language has been adapted to be more modern, and the units of measure have been converted to metric.
13grams of zinc bromide are dissolved in 29.6 ml of alcohol. Four or five drops of nitric acid are added. This is added to half the collodion made above.
21.4grams of silver nitrate are dissolved in 7.4 ml of water. 29.6 ml of alcohol are added. This is then poured into the other half of the collodion; the brominated collodion is dropped in, slowly, while stirring.
The result is an emulsion of silver bromide. It is left to ripen for 10 to 20 hours until it attains a creamy consistency. It may then be used or washed, as outlined below.
To wash, the emulsion is poured into a dish and the solvents are evaporated until the collodion becomes gelatinous. It is then washed with water, followed by washing in alcohol. After washing, it is redissolved in a mixture of ether and alcohol and is then ready for use.
Emulsions created in this manner could be used wet, but they were often coated on the plate and preserved in similar ways to the dry process. Collodion emulsion plates were developed in an alkaline developer, not unlike those in common use today. An example formula follows.
When needed for use, mix 0.37 ml of A, 2.72 ml of B, and 10.9 ml of C. Flow this over the plate until developed. If a dry plate is used, first wash the preservative off in running water.[citation needed]
A photograph is an image created by light falling on a photosensitive surface, usually photographic film or an electronic image sensor, such as a CCD or a CMOS chip. Most photographs are now created using a smartphone or camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of what the human eye would see. The process and practice of creating such images is called photography.
Calotype or talbotype is an early photographic process introduced in 1841 by William Henry Fox Talbot, using paper coated with silver iodide. Paper texture effects in calotype photography limit the ability of this early process to record low contrast details and textures.
Photographic plates preceded photographic film as a capture medium in photography. The light-sensitive emulsion of silver salts was coated on a glass plate, typically thinner than common window glass. They were heavily used in the late 19th century and declined through the 20th. They were still used in some communities until the late 20th century.
Collodion is a flammable, syrupy solution of nitrocellulose in ether and alcohol. There are two basic types: flexible and non-flexible. The flexible type is often used as a surgical dressing or to hold dressings in place. When painted on the skin, collodion dries to form a flexible nitrocellulose film. While it is initially colorless, it discolors over time. Non-flexible collodion is often used in theatrical make-up. Collodion was also the basis of most wet-plate photography until it was superseded by modern gelatin emulsions.
The albumen print, also called albumen silver print, is a method of producing a photographic print using egg whites. Published in January 1847 by Louis Désiré Blanquart-Evrard, it was the first commercial process of producing a photo on a paper base from a negative, previous methods - such as the daguerreotype and the tintype - having been printed on metal. It 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 albumen photographic prints and paper in the United States.
The gelatin silver process is the most commonly used chemical process in black-and-white photography, and is the fundamental chemical process for modern analog color photography. As such, films and printing papers available for analog photography rarely rely on any other chemical process to record an image. A suspension of silver salts in gelatin is coated onto a support such as glass, flexible plastic or film, baryta paper, or resin-coated paper. These light-sensitive materials are stable under normal keeping conditions and are able to be exposed and processed even many years after their manufacture. The "dry plate" gelatin process was an improvement on the collodion wet-plate process dominant from the 1850s–1880s, which had to be exposed and developed immediately after coating.
A silver halide is one of the chemical compounds that can form between the element silver (Ag) and one of the halogens. In particular, bromine (Br), chlorine (Cl), iodine (I) and fluorine (F) may each combine with silver to produce silver bromide (AgBr), silver chloride (AgCl), silver iodide (AgI), and four forms of silver fluoride, respectively.
The ambrotype, 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. Following the invention of daguerreotypes, cheaper than the French invention, ambrotypes came to replace them. Like a print on paper, it is viewed by reflected light. Like the daguerreotype or 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 melanotype or ferrotype, is a photograph made by creating a direct positive on a thin sheet of metal, colloquially called 'tin', coated with a dark lacquer or enamel and used as the support for the photographic emulsion. It was introduced in 1853 by Adolphe Alexandre Martin in Paris, like the daguerreotype was fourteen years before by Daguerre. The daguerreotype was established and most popular by now, though the primary competition for the tintype would have been the ambrotype, that shared the same collodion process, but on a glass support instead of metal. Both found unequivocal, if not exclusive, acceptance in North America. Tintypes enjoyed their widest use during the 1860s and 1870s, but lesser use of the medium persisted into 1930s and it has been revived as a novelty and fine art form in the 21st century. It has been described as the first "truly democratic" medium for mass portraiture.
The term alternative process refers to any non-traditional or non-commercial photographic printing process. Currently, the standard analog photographic printing process for black-and-white photographs is the gelatin silver process. Standard digital processes include the pigment print, and digital laser exposures on traditional color photographic paper.
The history of photography began with the discovery of two critical principles: The first is camera obscura image projection, the second is the discovery that some substances are visibly altered by exposure to light. There are no artifacts or descriptions that indicate any attempt to capture images with light sensitive materials prior to the 18th century.
Hand-colouring refers to any method of manually adding colour to a monochrome photograph, generally either to heighten the realism of the image or for artistic purposes. Hand-colouring is also known as hand painting or overpainting.
The conservation and restoration of photographs is the study of the physical care and treatment of photographic materials. It covers both efforts undertaken by photograph conservators, librarians, archivists, and museum curators who manage photograph collections at a variety of cultural heritage institutions, as well as steps taken to preserve collections of personal and family photographs. It is an umbrella term that includes both preventative preservation activities such as environmental control and conservation techniques that involve treating individual items. Both preservation and conservation require an in-depth understanding of how photographs are made, and the causes and prevention of deterioration. Conservator-restorers use this knowledge to treat photographic materials, stabilizing them from further deterioration, and sometimes restoring them for aesthetic purposes.
Richard Leach Maddox was an English photographer and physician who invented lightweight gelatin negative dry plates for photography in 1871.
Photographic emulsion is a light-sensitive colloid used in film-based photography. Most commonly, in silver-gelatin photography, it consists of silver halide crystals dispersed in gelatin. The emulsion is usually coated onto a substrate of glass, films, paper, or fabric. The substrate is often flexible and known as a film base.
James Ambrose Cutting (1814–1867) was an American photographer and inventor, sometimes called the inventor of the Ambrotype photographic process.
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.
The practice and appreciation of photographyin the United States began in the 19th century, when various advances in the development of photography took place and after daguerreotype photography was introduced in France in 1839. The earliest commercialization of photography was made in the country when Alexander Walcott and John Johnson opened the first commercial portrait gallery in 1840. In 1866, the first color photograph was taken. Only in the 1880s, would photography expand to a mass audience with the first easy-to-use, lightweight Kodak camera, issued by George Eastman and his company.
The conservation and restoration of photographic plates is the practice of caring for and maintaining photographic plates to preserve their materials and content. The practice includes the measures that can be taken by conservators, curators, collection managers, and other professionals to conserve the material unique to photographic plate processes. This practice includes understanding the composition and agents of deterioration of photographic plates, as well as the preventive, and interventive conservational measures that can be taken to increase a photographic image's longevity.
↑ Michael R. Peres, ed. (2007). Focal encyclopedia of photography: digital imaging, theory and applications, history, and science (4thed.). Amsterdam: Focal. ISBN978-0-08-047784-8. OCLC499055803.{{cite encyclopedia}}: Missing or empty |title= (help)
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