Hubbry Logo
Collodion processCollodion processMain
Open search
Collodion process
Community hub
Collodion process
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Collodion process
Collodion process
Collodion process
View on Wikipedia
from Wikipedia
A collodion wet plate negative of Girona, Spain, c. 1867

The collodion process is an early photographic process for the production of grayscale images. The collodion process – mostly synonymized with the term "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 exposure times sometimes longer than a half hour were tolerable.[1]

History

[edit]
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

[edit]
Collodion process portrait of Congresswoman Deb Haaland in 2019, by Shane Balkowitsch. Haaland was United States Secretary of the Interior between 2021–2025.

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:

Advantages

[edit]
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

[edit]
Color rendering (collodion, color and standard black and white)
Collodion image of color checker

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. The silver bath consequently needed to be "refurbished" by exposing to bright sunlight and filtering.

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.[20]

Use

[edit]
North Sydney and Sydney Harbour, by C Bayliss B Holtermann, 1875, colossal collodion glass-plate negative
A positive of the same image

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.[21]

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.[22] 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.[23]

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.[24] Oskar Barnack Award winning photojournalist and contemporary collodion wet plate artist Charles Mason[25][26] finds an artistic appeal in the uncertainty of the results of a wet plate photograph that cannot be recreated with modern digital photography.[27] Mason says "If you plan it, then it becomes contrived, If you just let it happen, it's the gods helping you out."[28] In 2018 Mason completed an artist-in-residency program with Denali National Park where he produced 24 collodion wet plate images of the park.[29]

Search for a dry collodion process

[edit]

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 hours, or even days, after coating. They all possessed the chief disadvantage, that they rendered the plate extremely slowly. 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

[edit]
British veteran of the Napoleonic Wars 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

[edit]

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.[30] 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.[30]

Various substrates were tried including wood, and Australian photographers Alfred R. Fenton[31] and Frederick H. Coldrey patented a version on black leather in 1857 to create an unbreakable photograph that could be sent by mail.[32] 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.[30]

Collodion emulsion preparation example

[edit]
See also: Collodion § Wet-plate collodion photography

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.

  1. 4.9 grams of pyroxylin are dissolved in 81.3 ml of alcohol, and 148 ml of ether.
  2. 13 grams 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.
  3. 21.4 grams 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.
  4. 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.
  5. 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.

Part A: Pyrogallic acid 96 g, alcohol 1 oz.
Part B: Potassium bromide 12 g, distilled Water 30 ml
Part C: Ammonium carbonate 80 g water 30 ml

When needed for use, mix 0.37 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]

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Collodion process

View on Grokipedia
from Grokipedia
The collodion process, also known as the wet collodion or wet plate process, is a pioneering photographic technique invented in 1851 by English sculptor Frederick Scott Archer, which involves coating a plate with a solution of (nitrocellulose dissolved in and alcohol, sensitized with ), immersing it in to form light-sensitive , exposing it in a camera while still wet, and developing it immediately to produce detailed negative images that could be used to create positive prints, ambrotypes, or tintypes. Archer announced the process publicly without patenting it, allowing widespread adoption but leaving him unrecognized and financially strained until his death in 1857 at age 44. The method required the entire workflow—from coating and sensitizing the plate to exposure, development with pyrogallic acid under red light, fixing with , washing, drying, and varnishing—to be completed before the dried, typically within 15–20 minutes, making it labor-intensive yet capable of exposures as short as a few seconds in bright light. This process surpassed earlier techniques like the , which produced unique, non-reproducible metal positives with limited detail, and the , which used paper negatives prone to distortion from fiber texture; collodion on yielded sharper, higher-resolution images with the reproducibility of negatives for multiple prints. By the late 1850s, it had largely replaced the , enabling mass production and democratizing for portraits, landscapes, and documentation, with popularity peaking from the 1850s through the 1880s until superseded by the more convenient silver dry plate process. Key variants included the , a underexposed negative on glass backed with black material to appear as a positive, and the (or ferrotype), the same emulsion transferred to enameled iron for a durable, inexpensive alternative popular in studios and field . Its historical impact extended to fields like , science, and art, capturing pivotal events such as the and facilitating the growth of photographic studios worldwide.

History

Invention and Early Development

The collodion process emerged in the early 1850s as a significant advancement in , building on the limitations of prior techniques such as the calotype's negatives and the daguerreotype's unique metal positives. In 1850, French photographer theorized the use of —a solution of gun cotton () dissolved in and alcohol—as a coating for glass plates to create more sensitive negatives, an idea outlined in his treatise Traité pratique de photographie sur papier et sur verre. Le Gray's proposal, however, remained largely conceptual and untested at the time, stemming from his earlier experiments with negatives to improve image sharpness and reduce exposure times. English sculptor and photographer Frederick Scott Archer brought the process to practical fruition in 1851, conducting initial successful experiments that March. Archer's breakthrough involved applying as a viscous, light-sensitive binder for salts directly onto glass plates, producing negatives with finer detail and higher sensitivity than albumen-based alternatives. This innovation allowed exposures as short as a few seconds in bright light, a marked improvement over the minutes required by earlier methods. Meanwhile, French chemist Désiré Blanquart-Évrard had been refining albumen-sensitized paper processes since 1850, achieving chemically developed prints by 1851, but 's emulsion proved superior in speed and resolution, quickly overshadowing albumen for negative production. Archer publicly announced his wet collodion process in a detailed article, "On the Use of in ," published in The Chemist in March 1851, providing instructions for its preparation and use. He further demonstrated the technique at the in that September, showcasing glass plate negatives that highlighted its potential for high-quality reproductions. Notably, Archer declined to the invention, a decision that facilitated its immediate and widespread dissemination among photographers without legal or financial barriers, accelerating the shift from daguerreotypes to negative-positive workflows.

Widespread Adoption and Peak Era

Following its public disclosure in , the collodion process rapidly gained traction among photographers due to its ability to produce detailed negatives from which multiple prints could be made, surpassing the limitations of earlier methods like the . In , Frederick Scott Archer published a manual detailing the technique, which facilitated its widespread dissemination and establishment as the preferred method in British studios by the mid-1850s. This adoption was accelerated by the integration of collodion negatives with albumen printing on paper, introduced around 1850, allowing for efficient production of positive images with enhanced clarity and tonal range. The process's relative portability—requiring only a mobile for on-site development—enabled its use in field , marking a significant shift toward documentary work. British photographer employed wet collodion plates during the in 1855, capturing over 360 images of military camps, equipment, and landscapes under challenging conditions, which were exhibited to great acclaim upon his return. Similarly, in the United States, and his team utilized the collodion process extensively during the Civil War in the 1860s, producing thousands of glass negatives that documented battles, soldiers, and aftermath scenes, despite the logistical demands of wagon-mounted darkrooms. By the 1860s, collodion reached its peak as the dominant photographic technique, powering innovations like stereo views—which used paired negatives on glass slides for three-dimensional images—and the cartes de visite, small card-mounted portraits that fueled a collecting craze across and America. Economically, it drastically reduced costs compared to daguerreotypes by enabling unlimited reproductions from a single negative, transforming portraiture into an accessible commodity and spurring the growth of commercial studios. This era saw millions of images produced annually, solidifying collodion's role in everyday and artistic photography until the late 1870s. Tragically, Archer received no financial reward for his and died impoverished in 1857 at age 44, leaving his family without support.

Decline and Replacement

The collodion process's requirement for immediate wet processing—coating, sensitizing, exposing, and developing plates while the remained liquid—severely limited scalability and portability, confining it largely to studio or field setups with portable darkrooms and restricting widespread commercial expansion. This inherent constraint became increasingly apparent as evolved toward more efficient methods in the late . The pivotal advancement came with the invention of the gelatin dry plate process by English physician Richard Leach Maddox in 1871, who published a method for suspending in a that could be dried and stored for later use, eliminating the need for on-site preparation. Following Maddox's breakthrough, refinements by figures such as Charles Harper Bennett in 1878, who improved ripening for greater sensitivity, accelerated the transition. Commercial production of dry plates began in earnest around 1879–1880, with George Eastman's Eastman Dry Plate Company launching mass-manufactured plates that year, enabling consistent quality and broader accessibility for photographers. The process saw significant decline after 1880 as dry plates offered faster exposures (up to 10 times quicker) and simpler workflows, quickly dominating professional and amateur practice. By 1890, dry plates accounted for the vast majority of photographic work, supplanting in most applications due to their superior convenience and reliability. Despite this shift, lingered in specialized niches, such as large-format , where its fine grain and tonal depth remained valued for creating detailed prints from oversized negatives until around 1900. It also persisted in astronomical through the , particularly for capturing celestial spectra and lunar details, owing to the process's ability to produce high-resolution plates under controlled conditions. By the , however, even these holdouts had transitioned fully to dry plate and early technologies in professional settings, marking the complete obsolescence of wet collodion as a primary method.

Technical Process

Materials and Emulsion Preparation

The collodion process relied on a set of primary materials to create light-sensitive emulsions on glass plates. The core component was collodion, a viscous solution consisting of approximately 3-4% nitrocellulose (also known as gun cotton or pyroxylin, with the chemical formula C₆H₇(NO₂)₃O₅) dissolved in a 2:1 mixture by volume of diethyl ether and ethanol (ethyl alcohol). Other essential materials included a silver nitrate solution (typically 9-15% concentration in distilled water, adjusted to pH 4-6 with nitric or acetic acid) for sensitization, clean glass plates prepared by polishing with whiting (calcium carbonate) or etching with dilute nitric acid to ensure adhesion, developers such as pyrogallic acid or ferrous sulfate in aqueous-alcoholic solutions, and a fixer of sodium thiosulfate (hypo) at 15-20% concentration to remove unexposed halides. Preparation of the emulsion began with dissolving the to form plain , followed by the addition of salts to create a "salted" or iodized sensitive to light. A historical , representative of mid-19th-century formulations, involved dissolving 1 of gun in a mixture of 40 of and 25 of 95% , allowing several days for complete dissolution in a tightly sealed container under cool, dark conditions to prevent and formation. Once dissolved, 0.5 of (or a combination of and for broader ) were added and gently agitated until fully integrated, yielding a syrupy with akin to , suitable for flowing over plates. Alternative iodization used 2-3% alone for simpler setups, though salts improved stability and contrast in negatives. The resulting salted was stored in amber bottles away from light and heat, with a shelf life of weeks to months before the volatile solvents evaporated or the halides precipitated. Safety concerns were paramount during emulsion preparation due to the inherent hazards of the materials. Diethyl ether's high volatility ( 34.6°C) and flammability (explosive limits 1.9-36% in air) posed significant risks of and , particularly in poorly ventilated 1850s studios where ignition from open flames or static discharge was common, leading to documented incidents of laboratory blasts and studio s. itself was when dry, and caused severe skin burns and eye damage upon contact, necessitating gloves, goggles, and controlled environments to mitigate these dangers.

Sensitization, Exposure, and Development

Once the iodized is prepared, begins by pouring the viscous solution onto a clean plate in a , allowing it to flow evenly across the surface before draining the excess back into the reservoir. The plate is then immediately immersed in a sensitizing bath, typically a 9-10% solution of in , for 1-2 minutes to react with the in the collodion and form light-sensitive crystals on the surface. Excess is drained from the back of the plate, and it is allowed to dry slightly in air to avoid streaks, preparing it for exposure while the collodion remains wet. The sensitized plate must be exposed in the camera within 5-10 minutes, as the begins to dry and lose sensitivity beyond this window, necessitating the entire wet plate workflow to occur in quick succession. Typical exposure times ranged from 10 to 60 seconds in bright sunlight, depending on the lens aperture—often f/4 or slower with period lenses like the Petzval—and lighting conditions, with the emulsion's sensitivity equivalent to ISO 1-5. For negative production, slight underexposure was preferred to maintain clear shadows and minimize chemical fog during development. Development follows immediately after exposure, typically in a portable tent to shield from light while allowing fieldwork mobility. The plate is removed from the camera holder and a developer—commonly an acidic solution or, in earlier formulations, pyrogallic acid—is poured evenly over the surface, which is gently rocked to ensure uniform reduction of the exposed silver halides to metallic silver, revealing the within 10-30 seconds. Once the image density is sufficient, development is halted by rinsing the plate in clean water, followed by immersion in a (hypo) fixing bath to dissolve unexposed halides and stabilize the image.

Post-Processing and Fixing

After development, the collodion plate undergoes fixing to stabilize the image by removing unexposed silver halides. This is achieved by immersing the plate in a 15-20% solution of (hypo) for 5-10 minutes, during which the fixer converts the halides into soluble complexes that can be rinsed away. Subsequent washing is essential to eliminate residual fixer and silver-thiosulfate complexes, preventing long-term image degradation such as or staining from hypo retention. The plate is rinsed in several changes of , typically for 10-15 minutes total, in a dust-free environment to avoid particulate contamination during air drying. To protect the delicate emulsion from physical damage and environmental factors, the dried plate is varnished with a thin coat of plain or spirit applied by flowing it evenly over the surface. A standard historical spirit recipe involves dissolving 1 ounce of gum in 16 ounces of alcohol, creating a clear protective layer that enhances durability without altering the image tone. Historically, incomplete removal of hypo during led to residue buildup, which accelerated deterioration through chemical with atmospheric moisture and pollutants. In modern revivals of the process, is frequently used as an alternative fixer for its faster action, typically requiring 2-5 minutes, while still allowing effective stabilization.

Image Formats and Variants

Negatives for Printing

The collodion process produced glass plate negatives that created a reversal image, where light areas in the subject appeared dark and vice versa when viewed by transmitted light, serving as an ideal matrix for generating multiple positive prints. These negatives were coated on clear glass supports, typically 3 to 6 mm thick, allowing for sharp detail transfer during printing. The medium offered exceptional resolution due to the fine grain of the collodion emulsion, which minimized granularity and supported intricate pictorial reproduction. For optimal printing, the negatives provided sufficient opacity in shadow areas while maintaining transparency in highlights to facilitate contact printing. Printing from these negatives typically involved contact exposure onto albumenized paper, which was first coated with egg white and then sensitized in a silver nitrate solution to form light-sensitive silver halides. The negative was placed in direct contact with the paper in a printing frame and exposed to ultraviolet light from the sun, requiring 5 to 20 minutes depending on weather conditions and the negative's density, as the printing-out process gradually developed the image through light action alone. This method produced warm-toned positive prints with fine detail, fixed afterward in a sodium thiosulfate bath to stabilize the silver image. The ability to reuse a single durable glass negative enabled mass production of prints, revolutionizing photography's commercial potential in the mid-19th century. By the 1860s, collodion negatives were instrumental in supplying images for illustrated newspapers, where photographs served as references for wood engravings that could be reproduced in print runs of thousands, as seen in publications like . Landscape photographers pushed the format's limits with "mammoth" plates up to 20 by 24 inches, capturing expansive scenes while balancing the challenges of handling large, heavy glass sheets during the wet process. A prominent historical example is ' Yosemite series from the 1860s, produced using 18 by 22-inch wet collodion negatives that yielded thousands of albumen prints, influencing public and congressional support for preserving the valley as a .

Ambrotypes and Direct Positives

The , also known as a , is a unique direct positive on produced via the wet process, distinct from negatives intended for multiple copies. It achieves its positive appearance through deliberate underexposure of the collodion plate during camera exposure, resulting in a low-density negative after development; this low contrast ensures that the lighter tones transmit sufficient to create highlights when viewed. The developed and fixed plate is then backed with a dark material, such as black lacquer, velvet, or painted backing, which absorbs in the shadowed areas of the negative, reversing the image to simulate a positive . This technique was developed around 1852 by American inventor James Ambrose Cutting of Boston, Massachusetts, who secured three U.S. patents (numbers 11,213, 11,266, and 11,267) in 1854 for improvements in producing photographic images on glass using , including methods for adhering backings and varnishing. Ambrotypes were typically produced in sizes ranging from approximately 2x4 inches (common for smaller portraits) to 8x10 inches (for larger formats), and they were housed in protective cases similar to those used for daguerreotypes. When held up to a light source, the dark backing prevents transmission through the image's shadowed regions, enhancing the illusion of depth and tonal range in the final positive view. Ambrotypes gained widespread popularity from 1855 to 1865 as an affordable alternative for portraiture, offering a cost-effective option compared to the more expensive and labor-intensive , with prices often ranging from 25 cents to $2.50 per . Their appeal lay in the ability to produce detailed, one-of-a-kind positives quickly using readily available plates, making them accessible to middle-class sitters seeking personal mementos. A notable variation, the opalotype (or opaltype), employed —a translucent white —for the substrate, diffusing the to create a softer, more ethereal effect often enhanced with hand-applied color; this adaptation was patented in by Glover and Bold in and further popularized the format for decorative portraits.

Ferrotypes (Tintypes)

Ferrotypes, commonly referred to as tintypes, represent a variant of the collodion process that produces direct positive images on thin sheets of enameled iron, prized for their robustness and low cost compared to alternatives. Invented in 1853 by French photographer Adolphe-Alexandre Martin, ferrotypes quickly gained traction as a portable medium for portraiture, allowing photographers to create durable images without the fragility of glass supports. The process coats a japanned iron sheet—pre-treated with a dark —with a emulsion containing light-sensitive silver halides, followed by sensitization in a bath. After brief exposure in the camera, the plate is developed to form an underexposed negative that appears as a positive against the opaque metal background, requiring no additional backing material. These images were characteristically small and compact, typically measuring from 1 by 2 inches up to 5 by 7 inches, making them ideal for personal keepsakes or inclusion in albums. Exposures lasted 5 to 15 seconds in daylight conditions, enabling quick sittings that suited busy subjects. To safeguard the from tarnishing and physical damage, ferrotypes were routinely varnished with a thin protective layer of dissolved in alcohol. Their popularity peaked from the 1860s through the 1890s, particularly among itinerant photographers who operated mobile studios at fairs, beaches, and public events, capitalizing on the process's simplicity and speed. Unlike the more delicate glass ambrotypes, which shared a similar direct-positive technique, ferrotypes endured longer due to the inherent strength of their metal substrate, resisting breakage during transport and handling. This durability extended their use into arcade and photography well into the , outlasting many contemporaneous formats as affordable snapshots for vacationers and passersby.

Advantages and Limitations

Key Advantages

The collodion process marked a significant advancement in due to its enhanced sensitivity to light, which drastically reduced exposure times compared to the . While often required several minutes of exposure in bright sunlight, the collodion wet plate process typically needed only 20 to 60 seconds for portraits, even in indoor settings with diffused light, making it feasible to capture subjects without prolonged bracing or head clamps. This improvement in speed democratized portraiture by allowing more natural expressions and broader accessibility beyond outdoor sessions. In terms of cost efficiency, the process utilized inexpensive glass plates as a support medium, replacing the costly silvered copper plates of the , and enabled the production of unlimited positive prints from a single negative. By the mid-1850s, ambrotypes and tintypes derived from cost as little as 12 cents each, a fraction of the 's typical $2.50 price, representing a substantial reduction that spurred and widespread adoption. This negative-positive workflow eliminated the one-off nature of , allowing photographers to scale operations economically. The image quality achieved with collodion surpassed predecessors through its fine grain structure and high resolution, yielding sharp details suitable for enlargements and views. Supported on clear , the produced images with superior clarity and a wide tonal range, capturing subtle gradations that enhanced artistic and documentary potential. Furthermore, the process's versatility stemmed from its ability to generate both durable negatives for multiple copies and direct positives like ambrotypes on or tintypes on metal, adapting to various formats without specialized beyond a portable . This flexibility facilitated field photography and diverse applications, solidifying collodion's dominance until the .

Principal Disadvantages

The collodion process, being a wet plate technique, required that the be coated, sensitized, exposed, and developed within a narrow window before it dried, typically 10 to 15 minutes, necessitating a portable at the site of and rendering fieldwork cumbersome, especially for travel or remote locations. The chemicals involved posed significant hazards, with the collodion solution—composed of gun-cotton dissolved in and alcohol—being highly flammable, leading to frequent studio fires in the and due to ignition risks near open flames or lights during preparation and processing. fumes were toxic, accumulating in poorly ventilated darkrooms and causing chronic issues among photographers, including nervous system damage, biliousness, stomach spasms, extreme nervousness, impaired eyesight, and paralysis-like conditions, with some practitioners reporting prolonged misery lasting years from repeated exposure. The process demanded considerable skill, as precise timing for , immersion in the bath (often 20 seconds to 2 minutes depending on ), exposure (typically 4 to 8 seconds in bright ), and development was essential under clean conditions to avoid imperfections like fogging, spots, or uneven films, resulting in a high failure rate where many plates were ruined by minor errors in execution. While smaller sizes were common for portraits, larger plates up to 160x96.5 cm were produced for landscapes and panoramas, though handling and challenges limited widespread use of very large formats. Additionally, the was sensitive to environmental factors, performing best at temperatures of 60 to 70°F, with hotter conditions accelerating drying and causing reticulation or , while colder slowed reactions and required formula adjustments. Lack of early standardization exacerbated these issues, as formulas and procedures varied widely until the , when commercial preparations and shared practices among began to provide more consistent results, though chronic exposure risks persisted without modern safety measures.

Applications and Uses

Commercial Portraiture

The collodion process revolutionized commercial portraiture by enabling rapid production in both mobile and fixed studio environments, making accessible to a broader clientele. For tintypes, itinerant photographers often operated from mobile wagons, which served as self-contained units equipped with chemical baths, sensitizing solutions, and development trays, allowing them to travel to rural areas and events for on-site portraits. These wagons, typically horse-drawn and fitted with light-tight compartments, facilitated the wet collodion workflow—coating iron plates, sensitizing in , exposing, and fixing—within the critical 15-minute window before the dried. In contrast, fixed urban studios specializing in ambrotypes relied on permanent setups with large chemical baths for immersing glass plates in , , developer, and fixer, providing a more controlled environment for higher-quality positives backed with varnish or paper. The process significantly impacted the market through the format, sparking a "cardomania" craze from the mid-1850s to the late that democratized portraiture and imagery. Photographers produced an estimated 300 to 400 million cartes annually during the peak, with multiple small prints (typically 2¼ x 3½ inches) exposed on a single glass negative and printed on albumen paper, enabling mass distribution at low cost. Prices for collodion-based portraits, including cartes, ambrotypes, and tintypes, fell to as low as $0.25 per image by 1860, compared to earlier costs of several dollars, fueling widespread adoption among middle-class families and collectors who traded cards like modern trading cards. Key innovator André-Adolphe-Eugène Disdéri patented the system in , designing a multi-lens camera that captured up to eight images on one 8x10-inch negative, allowing studios to produce hundreds of prints daily from a single exposure and transforming portraiture into an efficient commercial enterprise. By the 1860 U.S. Census, the proliferation of techniques had led to hundreds of photographic galleries nationwide, reflecting the process's dominance in the industry. The simplicity of production, requiring minimal equipment beyond portable baths and plates, also enabled women's entry into professional photography, with many operating independent studios or assisting in family businesses to capture affordable portraits for everyday sitters.

Scientific and Documentary Photography

The collodion process played a pivotal role in early astronomical photography, particularly for capturing faint celestial objects through long exposures. In the 1870s, astronomers at the Observatory utilized wet collodion plates attached to telescopes to record stellar images, overcoming the process's limitations for extended exposures despite its wet-plate constraints that required immediate development. This application allowed for detailed documentation of star positions and nebulae, contributing to foundational catalogs of the before the widespread adoption of dry plates improved sensitivity and convenience. In scientific imaging, enabled advancements in photomicrography, where thin slides coated with the captured magnified specimens for study and projection. Early practitioners prepared collodion negatives directly from views, producing high-resolution images of biological and samples that were then contact-printed onto lantern slides for educational shows. This technique's fine grain and clarity made it ideal for preserving microscopic details, supporting research in , , and throughout the mid- to late . Documentary applications of collodion extended to motion studies and expeditionary records, leveraging the process's portability for field work. Photographer employed large wet plates in the 1870s to sequence , using multiple cameras triggered sequentially to capture phases of movement, such as a horse's gallop, which proved all four hooves could leave the ground simultaneously. These 1878 experiments at Leland Stanford's farm marked a breakthrough in analyzing motion scientifically, with 's detail essential for the resulting sequential negatives. Felice , a pioneering war photographer, used collodion negatives during subsequent conflicts including the Second Opium War (1856–1860) and Sino-Japanese War (1894–1895) to document battlefields, capturing stark images of destruction and military life that informed public understanding of distant events. The process's durability and sharpness sustained its use in field science during polar expeditions into the , where portable setups allowed on-site processing amid harsh conditions. voyages, such as those in the late , relied on wet for recording ice formations, , and expedition progress, valuing its resistance to environmental stresses over emerging dry alternatives. This persisted until the commercial availability of dry plates in the gradually supplanted , offering greater ease for remote scientific documentation without compromising archival quality.

Developments in Dry Collodion

Historical Searches and Experiments

Efforts to develop a dry variant of the process began shortly after Frederick Scott Archer introduced the wet method in , driven by the need to eliminate the cumbersome requirement for immediate exposure and development while the remained wet. Early experimenters sought additives to preserve the 's sensitivity after drying, focusing on substances that could retain moisture or stabilize the silver halides without compromising image quality. In 1854, British photographers George Shadbolt and Farnham Maxwell Lyte independently proposed methods using diluted in water or combined with glycerine to coat sensitized plates, allowing them to retain sensitivity for several hours to a few days, though exposures were typically three times longer than wet . The following year, French photographer Jean-Marie Taupenot introduced a , in which a sensitized plate was overcoated with iodized albumen, dried, and could be stored for weeks; however, development required up to 12 hours, limiting practicality. By 1856, John Dillwyn Llewelyn developed the oxymel , applying a mixture of and acetic acid to extend viability to days, while Richard Hill Norris experimented with incorporating and or , achieving storage for months but still with reduced speed compared to wet plates. During the 1860s, further trials incorporated albumen or early forms of to enhance emulsion stability, as photographers grappled with the inherent volatility of . A notable advancement came in 1864 when William B. Bolton and B.J. Sayce described a , dispersing in with as a binder, which allowed plates to be prepared in advance and marked a step toward more reliable dry media, though initial versions suffered from uneven sensitivity. Around 1870, the British photographic community, including members of the Photographic Society of (later Photographic Society), conducted comparative trials of these variants, evaluating additives like sugars and proteins for field use. Persistent challenges hindered widespread adoption, including emulsion cracking upon drying, which disrupted evenness, and a progressive loss of sensitivity, often rendering plates usable only for 24 to 48 hours post-preparation. These issues stemmed from 's tendency to contract and the instability of silver salts in desiccated conditions, forcing experimenters to balance preservation with efficacy through iterative testing of hygroscopic agents like glycerin and sugars. Despite partial successes, most dry methods remained niche, as they could not fully replicate the wet process's speed and detail without specialized handling.

Outcomes and Transition to Gelatin Plates

Despite numerous experiments in the mid-19th century, efforts to develop viable dry collodion processes ultimately failed due to significant limitations, including a significant reduction in sensitivity, typically requiring 3 to 6 times longer exposures compared to wet collodion plates, and challenges in achieving even coatings, which rendered them unsuitable for widespread commercial use. The path forward emerged from these shortcomings with the invention of the gelatin dry plate. In 1871, English physician Richard Leach Maddox published a method in the British Journal of Photography for creating an emulsion of silver bromide suspended in , which could be coated onto plates and allowed to dry for later and exposure, offering a stable alternative to collodion-based materials. This innovation gained commercial traction beginning in , when British firm Wratten and Wainwright initiated large-scale production of dry plates in , followed by American manufacturers like the Eastman Dry Plate Company, which began operations in 1880 after George patented a for efficient coating. The gelatin dry plates revolutionized photography by increasing light sensitivity approximately 20 to 60 times over plates, enabling shorter exposures and eliminating the need for immediate processing, which accelerated the phase-out of collodion processes by the mid-1880s. Eastman's 1880 production of dry plates supported early portable cameras, laying the groundwork for consumer , while collodion techniques saw declining patents and use, becoming obsolete by the 1890s as dominated the field.

Modern Revival

20th-21st Century Interest

In the early , as -based processes displaced , museums and archives initiated preservation efforts to safeguard examples of this foundational technique, particularly during the and when prints were still occasionally produced for specialized applications like portraiture and scientific documentation. Institutions such as the Getty Conservation Institute documented -on-paper materials from this era. These efforts reflected growing academic recognition of 's in 's evolution, with collections at places like the including prints amid the shift to modern papers in the 1910s-; stable storage conditions like cool temperatures of 32–40°F (0–4°C) and 30–40% relative humidity help prevent degradation of the nitrate-based emulsions. Interest waned mid-century but revived in the 1970s through hobbyist and collector initiatives, notably by Mark Osterman, who began researching historic photographic processes while studying at the . Osterman's experiments, starting in 1987 alongside France Scully Osterman, focused on reconstructing wet-plate collodion techniques, leading to the establishment of Scully & Osterman Studio in 1991 and publications like The Collodion Journal (1995-2002), which disseminated knowledge on the process's history and . This period marked an intermittent academic and enthusiast resurgence, bridging 19th-century practices with contemporary experimentation. The 21st-century revival gained momentum driven by digital fatigue among photographers seeking tactile, unpredictable alternatives to instant digital capture, as well as of 's handmade —its rich tonal depth, imperfections, and one-of-a-kind positives evoking authenticity in an era of algorithmic editing. Workshops proliferated since the early 2000s, with hosting its first public collodion sessions in 1995 under Osterman's guidance and continuing them annually to teach ambrotypes and tintypes. The 2010s saw a boom fueled by accessible online tutorials on platforms like , including step-by-step guides from 2013 onward that democratized the process for hobbyists. Post-2000 practices, informed by OSHA guidelines limiting ethyl exposure to 400 ppm over eight hours, prompted reductions in ether content through alcohol-based dilutions and ventilated workflows, making the hazardous more viable for modern users. As of 2025, the revival persists with ongoing annual workshops and events, including the Wet Plate Jamboree and features of contemporary artists.

Contemporary Techniques and Artists

In contemporary practice, the wet plate collodion process has seen adaptations aimed at enhancing safety and practicality while preserving its analog essence. Practitioners have shifted toward less volatile solvents, such as combined with and cellosolve, to reduce the risks associated with highly flammable traditionally used in collodion formulas. LED safelights, often in red or orange wavelengths to match the process's sensitivity to blue and ultraviolet light, have become standard in darkrooms to minimize fogging without relying on older incandescent options. Additionally, digital scanning of finished plates using DSLR cameras or flatbed scanners provides high-resolution backups, allowing artists to archive unique one-of-a-kind images while enabling reproductions or enlargements through modern printing. Notable artists continue to advance the medium through personal exploration and education. has employed wet plate for intimate portraits since the late , leveraging its imperfections—such as drips and textures—to evoke emotional depth in series like (late –), where she exposes large-format negatives outdoors to capture landscapes and figures with a haunting, historical . John Coffer, a master tintyper based in , offers hands-on workshops at his Camp Tintype studio, teaching techniques for tintypes, ambrotypes, and negatives to hundreds of students annually since the , emphasizing practical mastery of the full wet plate workflow. Christina Z. Anderson, an educator and author, integrates into her broader alternative processes curriculum, detailing its applications through workshops and texts on hybrid analog methods as of her publications up to 2022. Community events foster innovation and skill-sharing among enthusiasts. The annual Wet Plate Jamboree, held since 2012 at John Coffer's Camp Tintype in , New York, draws dozens of participants for intensive three-day gatherings focused on collaborative shooting, formula experimentation, and troubleshooting, often resulting in shared advancements like optimized developer recipes. Commercially, portraits remain viable, with studios charging $100 to $500 per plate depending on size and complexity—for instance, 4x5-inch sessions at $150 and 8x10-inch at $300—catering to clients seeking heirloom-quality images for , events, or personal milestones. Hybrid approaches blending collodion with digital tools have expanded accessibility; photographers like Dylan Burr use digital sensors behind wet plates or post-process scans to create faster exposures and multiple variants from a single analog capture, as seen in his wedding photo booths. The process has also influenced , where its tactile, imperfect aesthetic adds vintage allure to modern editorials, such as collaborations featuring wet plate portraits of designers' collections to evoke 19th-century glamour. However, environmental concerns persist due to the generation of , including residues and potentially cyanide-forming fixers, requiring practitioners to adhere to local regulations for neutralization and disposal to prevent and contamination.

References

  1. https://hnoc.org/virtual-exhibitions/from_daguerreotype_to_digital/wet-plate-process
  2. https://smarthistory.org/the-collodion-5-of-12/
  3. https://rmc.library.cornell.edu/DawnsEarlyLight/exhibition/massproduction/index.html
  4. https://www.cameramuseum.ch/en/discover/permanent-exhibition/the-origins-of-photography/a-new-process-in-1850-wet-collodion/
  5. https://rps.org/about/history/
  6. https://cool.culturalheritage.org/albumen/library/monographs/masters/notes.html
  7. https://www.metmuseum.org/essays/the-rise-of-paper-photography-in-1850s-france
  8. https://www.iphf.org/hof-frederick-scott-archer
  9. https://www.vam.ac.uk/articles/photographic-processes
  10. https://cool.culturalheritage.org/albumen/technology/
  11. https://www.rct.uk/collection/exhibitions/roger-fentons-photographs-of-the-crimea/the-queens-gallery-buckingham-palace/fentons-photographic-process
  12. https://www.metmuseum.org/essays/photography-and-the-civil-war-1861-1865
  13. http://www.earlyphotography.co.uk/site/entry_C646.html
  14. https://www.gallery.ca/photo-blog/collecting-cards-cartes-de-visite
  15. https://blog.scienceandmediamuseum.org.uk/photography-a-z-frederick-scott-archer-wet-collodion-process/
  16. https://notquiteinfocus.com/2014/04/23/a-brief-history-of-photography-part-5-dry-plate-photography/
  17. http://www.earlyphotography.co.uk/site/gloss13.html
  18. https://www.conservation-wiki.com/wiki/Gelatin_Dry-plate_Negative
  19. https://fiveable.me/history-of-photography/unit-1/gelatin-dry-plate-process/study-guide/LGZb9ubgkq5jllFN
  20. https://www.acs.org/education/whatischemistry/landmarks/eastman-kodak.html
  21. https://siarchives.si.edu/blog/highlight-photo-cold-vault-gelatin-dry-plate-negatives
  22. https://rmc.library.cornell.edu/DawnsEarlyLight/exhibition/modernphotography/index.html
  23. https://adsabs.harvard.edu/full/1999JHA....30...93H
  24. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/nitrocellulose
  25. https://www.britannica.com/technology/wet-collodion-process
  26. https://unblinkingeye.com/Articles/WPC/WPC2/wpc2.html
  27. https://www.alternativephotography.com/the-wetplate-collodion-process/
  28. https://www.alternativephotography.com/wet-plate-collodion-process-ambrotypes/
  29. https://intrepidcamera.co.uk/blogs/guides/rikard-osterlunds-guide-to-wet-plate-collodion
  30. http://thephotopalace.blogspot.com/2016/12/effects-of-exposure-and-development.html
  31. https://bbhphoto.org/2018/03/17/the-portable-darkroom/
  32. https://cool.culturalheritage.org/albumen/library/monographs/sunbeam/chap16.html
  33. https://www.lundphotographics.com/index.php/sodium-thiosulfate-hypo.html
  34. https://www.getty.edu/conservation/publications_resources/pdf_publications/pdf/atlas_collodion.pdf
  35. http://static1.1.sqspcdn.com/static/f/695156/24768559/1398170991670/VarnishedTruth.pdf
  36. https://www.lundphotographics.com/index.php/blog/getting_started/fixing_plates.html
  37. https://cool.culturalheritage.org/albumen/library/monographs/sunbeam/chap22.html
  38. https://www.conservation-wiki.com/wiki/Collodion_Negative
  39. https://www.researchgate.net/publication/296328598_The_wet_collodion_process_-_A_scientific_approach
  40. https://www.getty.edu/conservation/publications_resources/pdf_publications/pdf/atlas_albumen.pdf
  41. https://www.archives.gov/research/still-pictures/still-picture-photographic-prints
  42. https://mds.marshall.edu/cgi/viewcontent.cgi?article=1208&context=colaconf
  43. https://capitolmuseum.ca.gov/experiences/exhibits/lasting-impressions-early-photography-in-california/mammoth-plates/
  44. https://www.metmuseum.org/exhibitions/listings/2014/carleton-watkins
  45. https://www.loc.gov/collections/liljenquist-civil-war-photographs/articles-and-essays/ambrotypes-and-tintypes/
  46. https://www.conservation-wiki.com/wiki/Ambrotype_%28Positive_Collodion%29
  47. https://psap.library.illinois.edu/collection-id-guide/directimage
  48. https://guides.library.oregonstate.edu/earlyphotoformats/ambrotypes
  49. https://fourtoes.co.uk/iblog/cutting-patent-ambrotypes/
  50. https://www.loc.gov/static/collections/liljenquist-civil-war-photographs/articles-and-essays/ambrotypes-and-tintypes/
  51. https://blog.scienceandmediamuseum.org.uk/find-out-when-a-photo-was-taken-identify-collodion-positive-ambrotype/
  52. https://www.conservation-wiki.com/wiki/Opalines%2C_Opaltypes%2C_Opalotypes
  53. http://historiccamera.com/cgi-bin/librarium2/pm.cgi?action=app_display&app=datasheet&app_id=2000
  54. https://blog.scienceandmediamuseum.org.uk/find-out-when-a-photo-was-taken-identify-ferrotype-tintype/
  55. https://rmc.library.cornell.edu/DawnsEarlyLight/exhibition/processes/tintype.html
  56. http://www.graphicsatlas.org/identification/?process_id=280
  57. https://www.ohiohistory.org/what-do-you-know-about-tintypes/
  58. https://www.conservation-wiki.com/wiki/Tintype
  59. https://www.edinphoto.org.uk/1_early/1_early_photography_-_processes_-_tintype.htm
  60. https://collections.libraries.indiana.edu/wyliehouse/exhibits/show/early-photography-wylie/dag-ambro-tin
  61. https://www.realorrepro.com/article/Photographic--Images
  62. https://www.eastman.org/photographic-processes-video-series-glossary
  63. https://www.archives.gov/research/still-pictures/still-picture-glass-holdings
  64. https://smarthistory.org/early-photography-niepce-talbot-and-muybridge/
  65. https://lithub.com/flashes-of-brilliance-the-19th-century-innovations-that-shaped-modern-photography/
  66. http://www.eshph.org/wp-content/uploads/2024/08/PHR41_Jennifer_Tucker.pdf
  67. https://www.oxfordreference.com/display/10.1093/oi/authority.20110803095926252
  68. https://www.gutenberg.org/files/63710/63710-h/63710-h.htm
  69. https://geoffbarker.wordpress.com/2023/11/30/the-nineteenth-centurys-largest-glass-plate-negatives/
  70. https://www.bostick-sullivan.com/wp-content/uploads/2022/03/wet-plate-instructions.pdf
  71. https://timlaytonfineart.com/wet-plate-collodion-negatives/
  72. https://daily.jstor.org/fast-cheap-and-totally-popular-tintypes/
  73. https://ohiomemory.ohiohistory.org/archives/5996
  74. https://rmc.library.cornell.edu/DawnsEarlyLight/exhibition/celebculture/index.html
  75. https://adsabs.harvard.edu/full/1898PASP...10..213B
  76. https://meridian.allenpress.com/aplm/article/139/12/1558/128823/Microscopic-Image-Photography-Techniques-of-the
  77. https://resources.culturalheritage.org/pmgtopics/1999-volume-eight/08_01_Long.html
  78. https://www.getty.edu/art/exhibitions/beato/
  79. https://link.springer.com/chapter/10.1007/978-3-031-11317-8_9
  80. http://www.earlyphotography.co.uk/site/gloss7.html
  81. https://new.photography/articles/dry-plates/
  82. https://www.kodak.com/en/company/page/history/
  83. https://www.conservation-wiki.com/wiki/Gelatin_Dry-plate
  84. https://psap.library.illinois.edu/collection-id-guide/photoprint
  85. https://rochester.makerfaire.com/maker/entry/156/
  86. https://www.collodion.org/scully-osterman
  87. https://www.fosters.com/story/lifestyle/home-garden/2013/11/04/dark-moody-collodion-photos-make/42063429007/
  88. https://www.eastman.org/event/workshops/tintypes-basics-0
  89. https://fstoppers.com/portraits/step-step-guide-wet-plate-photography-2540
  90. https://www.sentryair.com/blog/industry-applications/chemical-solvents/collodion-adhesive-possible-health-effects-fume-extraction-recommendations/
  91. https://www.analogforevermagazine.com/features-interviews/wet-plate-collodion-photographers-2024
  92. https://www.johncoffer.com/
  93. https://www.photrio.com/forum/threads/how-do-you-prepare-a-glass-plate-for-use-as-a-neg.10485/
  94. https://fourtoes.co.uk/iblog/collodion-darkroom-led-safelights/
  95. https://timlaytonfineart.com/2024/05/01/how-i-photography-my-wet-plate-collodion-tintypes/
  96. https://art21.org/read/sally-mann-collodion-process/
  97. https://www.christinazanderson.com/books/
  98. https://fourtoes.co.uk/iblog/wet-plate-jamboree-2012-dundee-new-york/
  99. https://www.moderntintype.photo/sessions
  100. https://dylanburr.com/blog/wet-plate-wedding-portraits-at-river-bend-lyons-colorado.html
  101. https://www.youtube.com/watch?v=Ic7UvmeZO8c
Add your contribution
Related Hubs
User Avatar
No comments yet.