The collodion process is an early photographic process, which was quickly replaced at the end of the 19th century with today's gelatin emulsion process. Theodore Roosevelt (ˈroʊzəvɛlt October 27 1858 January 6 1919 also known as T Photography (fә'tɒgrәfi or fә'tɑːgrәfi (from Greek φωτο and γραφία is the process and Art of recording pictures by means of capturing The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar This article is mainly concerned with Still photography film For Motion picture film please see Film stock.
The process is said to have been invented, almost simultaneously, by Frederick Scott Archer and Gustave Le Gray in about 1850. For people named Fred Archer (including the unrelated 20th-century photographer see Fred Archer. Jean-Baptiste Gustave Le Gray (August 30 1820 – July 30 1884 has been called "the most important French Photographer of the nineteenth century because of his technical For the game see 1850 (board game. 1850 ( MDCCCL) was a Common year starting on Tuesday (link In the following 30 to 40 years, it enjoyed widespread use, and was refined by many photographers and experimenters.
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The original idea
In 1851, Frederick Scott Archer introduced the wet plate process, sometimes referred to as the collodion process after the carrier material used. 1851 ( MDCCCLI) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian Calendar (or a Common year For people named Fred Archer (including the unrelated 20th-century photographer see Fred Archer. Collodion is a solution of Nitrocellulose in ether or Acetone, sometimes with the addition of Alcohols Its generic name is pyroxylin solution The process is very simple in concept. Bromide, iodide or chloride salts were dissolved in collodion, which is a solution of pyroxylin in alcohol and ether. Collodion is a solution of Nitrocellulose in ether or Acetone, sometimes with the addition of Alcohols Its generic name is pyroxylin solution Collodion is a solution of Nitrocellulose in ether or Acetone, sometimes with the addition of Alcohols Its generic name is pyroxylin solution This mixture was poured onto a cleaned glass plate, and allowed to sit for a few seconds. The plate was then placed into a solution of silver nitrate and water, which would convert the iodide, bromide or chloride salts to silver iodide, bromide or chloride, respectively. Once this reaction was complete, the plate was removed from the silver nitrate solution, and exposed in a camera while still wet. It was developed with a solution of iron sulfate, acetic acid and alcohol in water.
Advantages
It was the first widely used photographic process which resulted in a negative image on a transparent photographic medium. The other methods of its time, such as the Daguerreotype, produced a one-of-a-kind positive image, which could not be replicated easily. The daguerreotype (original French daguerréotype) is an early type of Photograph, developed by Louis Daguerre, in which the image is exposed directly WIth the collodion process, however, the photograper could make an unlimited number of prints from a single negative; this was typically done on albumen paper. The albumen print, also called albumen silver print, was invented in 1850 by Louis Désiré Blanquart-Evrard, and was the first commercially exploitable method
In addition to the convenience of creating negatives, the collodion process had numerous other advantages. It was an inexpensive process to work, especially in comparison with the daguerreotype. The polishing equipment and fuming equipment needed for the daguerreotype could be dispensed with entirely. The support for the images was glass, which was far less expensive than silver-plated copper, and was more consistent than paper for paper negatives. It was also fast for the time, requiring only seconds for exposure.
Disadvantages of the process
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 about 10 minutes, sometimes less, to complete everything. The plate would be dripping silver nitrate solution, causing stains and troublesome build-ups in the camera and plate holders. This made it an inconvenient process for field use, as it required a portable darkroom.
The silver nitrate bath was also a source of significant trouble. Through repeated use, it would become saturated with alcohol, ether, iodide and bromide salts, dust and various organic matter. It would lose effectiveness, and would often result in mysterious failures of plates to produce an image.
The collodion process becomes widely adopted
Despite its disadvantage, wet plate collodion became enormously popular. It was used for portraiture, landscape work, architectural photography and art photography.
It is, in fact, still used by a number of artists and experimenters, owing to its unique and sometimes unpredictable qualities.
The Dry Process
The extreme inconvenience of shooting wet collodion in the field led to many attempts to develop a dry collodion process, which could be shot and developed some time after coating. A large number of methods were tried, though none were ever found to be truly practical and consistent in operation. Even well-known scientists such as Joseph Sidebotham, Richard Kennett, Major Russell and Frederick Charles Luther Wratten attempted, but never met with good results.
Typically, these methods involved coating or mixing the collodion with a substance that would prevent it from drying quickly. For as long as the collodion remained at least partially wet, it would retain some of its sensitivity. Common processes involved chemicals such as glycerin, magnesium nitrate, tannic acid and albumen. Magnesium Nitrate is a Hygroscopic Salt with the formula Mg(NO32 Tannic acid, a commercial form of Tannin, is a Polyphenol. Its weak acidity ( pKa around 10 is due to these Phenol groups in Albumen redirects here For other uses see Albumen (disambiguation. Others involved more unlikely substances, such as tea, coffee, honey, beer and seemingly unending combinations thereof.
Many of these worked to an extent; they allowed the plate to be exposed hours, or even days, after coating. They all possessed one chief disadvantage, however: regardless of the process used, 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.
Collodion Emulsion
In 1864 W. Year 1864 ( MDCCCLXIV) was a Leap year starting on Friday (link will display the full calendar of the Gregorian Calendar (or a Leap year B. Bolton and B. J. Sayce published an idea for a process which would come to 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 would be 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 would react with a haloid salt; potassium iodide, for example. This would result in a double replacement reaction. The silver and iodine ions in solution would react, forming silver iodide on the collodion film. However, at the same time, potassium nitrate would also be formed by the potassium ions from the iodide and the nitrate ions from the silver. This salt could not be removed in the wet process. However, with the emulsion process, it could be washed out after 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 would behave the same way; the inconsistencies observed in the ordinary process were rare.
Collodion Emulsion preparation Example
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.
4. 9 grams of pyroxylin are dissolved in 81. Collodion is a solution of Nitrocellulose in ether or Acetone, sometimes with the addition of Alcohols Its generic name is pyroxylin solution 3 ml of alcohol, 148 ml of ether. In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Ether is a class of Organic compounds which contain an ether group — an Oxygen Atom connected to two (substituted Alkyl
13 grams of zinc bromide are dissolved in 29. Zinc bromide is a White Ionic solid. Uses Organic chemistry as a Lewis acid. 6 ml of alcohol. In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Four or five drops of nitric acid are added. Nitric acid ( H[[nitrate NO3]] also known as Aqua fortis and spirit of nitre, is a highly corrosive and This is added to half the collodion made above.
21. 4 grams of silver nitrate are dissolved in 7. Silver nitrate also known as lunar caustic is a soluble Chemical compound with Chemical formula Ag[[Nitrogen N]] O 3 4 ml of water. 29. 6 ml of alcohol are added. In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon This is then poured into the other half of the collodion; the brominized collodion dropped in, slowly, while stirring.
The result is an emulsion of silver bromide. Silver bromide (AgBr a soft pale-yellow insoluble salt well known (along with other silver halides for its unusual sensitivity to light. 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 a washing in alcohol. After washing, it is re-dissolved in a mixture of ether and alcohol, and is 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.
Part A:
Pyrogallic acid 96 g Alcohol 1 oz. Pyrogallol or benzene-123-triol is a white crystalline powder and a powerful reducing agent
Part B: Potassium bromide 12 g Distilled Water 30 ml
Part C: Ammonium carbonate 80 g Water 30 ml
When needed for use, mix 0. Potassium bromide ( K[[Bromine Br]] is a salt, widely used as an Anticonvulsant and a Sedative in the late 19th and early 20th centuries Ammonium carbonate is the commercial salt formerly known as sal volatile or salt of hartshorn. 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.
Chemical Reactions Involved in the Process
The reactions involved in the collodion processes are the same as those which apply generically to photographic processes as a whole.
The iodide, chloride or bromide salts in the collodion react with silver nitrate to produce silver iodide, silver chloride or silver bromide. Silver nitrate also known as lunar caustic is a soluble Chemical compound with Chemical formula Ag[[Nitrogen N]] O 3 Silver iodide ( Ag[[Iodine I]] is a Chemical compound used in Photography and as an Antiseptic in medicine Silver chloride is a Chemical compound with the Chemical formula Ag[[Chlorine Cl]] Silver bromide (AgBr a soft pale-yellow insoluble salt well known (along with other silver halides for its unusual sensitivity to light. These are unstable to light, and are chemically changed upon exposure. They are reduced to metallic silver by the developer.
References
- Contemporary Wet Plate Collodion Photography
- AlternativePhotography — Wetplate collodion process
- History of photography from 1839 to 1879
- Meier, Alf B. Basic Photography - a manual for the training of fashion photographers, (Frankfurt/M. : Jentzen oHG, 1992)
- An account of Sayce's process is to be found in the Photographic News of October 1865, or the Photographic Journal of the same date.
- The advantages of this salt were pointed out by Leon Warnerke in 1875. Leon Warnerke was a well-known 19th century currency forger who spent most of his career in south-east London.
- Modern ambrotype images and an overview on the wet-plate collodion process
- A brief history of the wet collodion process
- How the wet plate collodion process works
- KUTV video about wet plate photography
- Contemporary 19th Century Wetplate Collodion Photography
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