Wet Plate Collodion Negatives

The Collodion Dry Plate Negative Process emerged as an important evolution of the wet plate collodion process invented by Frederick Scott Archer in 1851.

Unlike wet plates, which had to be exposed and developed while still wet, dry plates allowed photographers to prepare plates in advance and develop them later, offering greater convenience and portability.

One of the early attempts to create a practical dry plate method came from Richard Hill Norris in 1856, who used tannin to preserve the collodion plates. However, his method was slow and not widely adopted. A more influential development occurred in 1862, when Captain J. H. Russell introduced a method of sensitizing collodion plates with silver nitrate and preserving them with a solution of tannin. This Russell Tannin Process allowed plates to remain sensitive for a longer period before exposure and extended the time photographers could wait before developing them. It was particularly valuable for landscape and expedition photographers working in remote areas without immediate access to darkroom facilities.

While Russell’s Tannin Process was a significant improvement over earlier attempts, it was eventually overshadowed by Dr. Richard Leach Maddox’s invention of the gelatin dry plate in 1871. The gelatin emulsion process was faster, more sensitive, and easier to use than the collodion-based processes. By the 1880s, commercially manufactured gelatin dry plates became widely available, gradually replacing collodion dry plates due to their greater sensitivity, convenience, and consistency. I provide chemistry and technical details for gelatin dry plates at the end of this article.

Nevertheless, Russell’s contributions were crucial in the progression from wet to dry plate photography, helping to establish the concept of preparing plates that could be stored and developed later—an essential stepping stone towards the gelatin dry plate revolution.

While 19th-century photographers eagerly pursued improvements in speed and convenience, most overlooked—or perhaps dismissed—the unique qualities of collodion dry plate negatives compared to the emerging silver gelatin dry plates. Yet, the visual aesthetic differences between the two processes are profound. Collodion dry plates, with their distinctive tonal range, luminous highlights, and fine detail, offer a visual character that is markedly different from the smoother, more uniform appearance of gelatin dry plates. The pursuit of efficiency and sensitivity came at the cost of these unique aesthetic qualities, which many photographers failed to appreciate amid the rapid technological advancements of the era. Today, we have the benefit of choosing our desired workflows for purely artistic reasons.

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Wet Plate Collodion Negatives Changed Photography

Major Russell first introduced the collodion dry plate process in 1861. I recommend downloading and reading his book, “The Tannin Process”, it’s totally free on Google Books as a PDF. I recommend reading “Collodion Processes, Wet & Dry” 1862 by Thomas Sutton. Everything I am doing today is based and built on the knowledge found in these two 19th-century books.

The negative at the top of this page is a collodion dry plate negative. It has that distinctive warm tone because of the tannic acid used in the dry plate process. The negatives directly below this paragraph are wet collodion negatives. Both were fixed in Potassium cyanide and developed with pyrogallic acid based developers. The only difference between the negatives is the tannic acid.

Wet Plate Collodion Chemistry

Wet Plate Collodion Chemistry For Negatives

COLLODION FULL & HALF BATCH (500ml/280ml)

• Wear a chemical-grade respirator/mask and mix outside if possible.
• Zero out the scale and add 2g/1g Cadmium Bromide (CdBr) to a small glass beaker with 3ml DH20.
• Cup the beaker in your hand and work it with a glass rod and break it up until it is fully dissolved. (Don’t get this airborne and breathe this because it can kill you!)
• Place the small beaker on the scale, zero it out again, and add 5g/2.5g of Ammonium Iodide (NH4I) or Cadmium Iodide (CdI).

Note: For collodion dry plate negatives, ammonium iodide (NH4I) ages the collodion emulsion faster (it goes to orange faster), which is great for negatives because it is good for contrast. The NH4I will dissolve in contact with CdBr.

For wet or dry negatives, I like to use NH4I rather than CdI; it’s more stable and will improve contrast. NH4I and CdBr are the winning tickets for wet or dry negatives, in my opinion. You can try a 50/50 mix of NH4I and CdI if you want to experiment and compare it to your other negatives.

• Add 130ml/80ml Everclear to a clean 1L glass beaker (solvent)
• Add 130ml/80ml Ether (must work in a well-ventilated area) (solvent)
• Note: I typically mix my Ether and Everclear 1L+1L upon receipt, so I would just use 260ml of the 1:1 solution for this.
• Pour a little of the solvents into the smaller salts glass beaker and then pour it back into the big beaker. This mixes the salts and solvents.
• Add 240ml/120ml (w/v) Plain USP Collodion into the beaker. (measure by volume, not by weight!!)
• Pour the collodion into my glass chemical storage bottle and ensure I have a smaller bottle as the drain bottle. Create a new label for both with the date and type of collodion.
• ** New collodion must sit for at least 24 hours before first use. I like to mix mine up at least one full week before use to allow it to ripen a little first.
• ** Store in a cool/dark place. Heat and light break down collodion.

** Reconstitution of Collodion in Drain Bottle: For the drain bottle collodion, you can reconstitute it at a rate of about 10% using the 1:1 Ether/Everclear solution. If I have 100ml in my drain bottle, I would add 10ml of my Ether/Everclear solution before use. I don’t pour this collodion into my original bottle, I just use it from this bottle and start another drain bottle.

Components of My Collodion Negative Formula

• Plain USP Collodion: This is a solution of pyroxylin (nitrocellulose) in a mixture of ether and alcohol. It serves as the film-forming agent.
• Everclear (ethanol): Acts as a solvent in the collodion mixture, reducing viscosity and aiding in the even coating of the plate.
• Ethyl Ether: Also a solvent, ether helps in dissolving the nitrocellulose and controls the drying rate of the collodion film.
• Cadmium Bromide (CdBr₂): A halide used in forming light-sensitive silver halides upon reaction with silver nitrate.
• Ammonium Iodide (NH₄I): Another halide which reacts with silver nitrate to form light-sensitive silver iodide.

Double Decomposition Chemistry

The photographic properties of the collodion dry plate come from the light-sensitive silver halides, which are formed by a double decomposition reaction (also known as metathesis) when the plate coated with halides is dipped into a solution of silver nitrate.

Reaction with Cadmium Bromide:

In this reaction, silver nitrate (AgNO₃) reacts with cadmium bromide to form silver bromide (AgBr) and cadmium nitrate (Cd(NO₃)₂). Silver bromide is a key light-sensitive material that darkens upon exposure to light, forming the latent image.

Reaction with Ammonium Iodide:

Here, silver nitrate reacts with ammonium iodide to produce silver iodide (AgI) and ammonium nitrate (NH₄NO₃). Silver iodide also forms part of the light-sensitive layer and is even more sensitive to light than silver bromide, enhancing the overall sensitivity of the photographic plate.

In the double decomposition reactions you are using to create your collodion dry plate negatives, cadmium nitrate and ammonium nitrate are byproducts formed alongside the light-sensitive silver halides (silver bromide and silver iodide). Here’s how they factor into the overall process:

Double Decomposition Reactions

Cadmium Bromide and Silver Nitrate:

• Product: Silver bromide (AgBr) is the light-sensitive agent.
• Byproduct: Cadmium nitrate (Cd(NO₃)₂).

Ammonium Iodide and Silver Nitrate:

• Product: Silver iodide (AgI) is the light-sensitive agent.
• Byproduct: Ammonium nitrate (NH₄NO₃).

Role and Impact of Byproducts

• Cadmium Nitrate (Cd(NO₃)₂): As a soluble compound, cadmium nitrate remains in the collodion layer but does not directly participate in the image formation process. Its presence does not have a significant impact on the photographic qualities of the emulsion. However, it could potentially influence the physical characteristics of the collodion layer, such as its granularity or the drying speed.
• Ammonium Nitrate (NH₄NO₃): Like cadmium nitrate, ammonium nitrate is also soluble and does not contribute to the light sensitivity or image formation. Its presence in the emulsion could affect the viscosity and drying behavior of the collodion film. In some cases, if the concentration is high, it might slightly influence the stability or shelf life of the prepared emulsion due to its hygroscopic nature, which could attract moisture.

Practical Considerations

When processing the plates, especially during washing, these byproducts are typically washed away. They do not interfere with the development and fixing processes where the image is made visible and permanent. In historical photographic processes, much attention is paid to the silver halides as they are crucial for the photochemical reactions upon exposure to light, but it’s good practice to understand the role of all chemicals involved to optimize your results.

While cadmium nitrate and ammonium nitrate are produced in the reactions, their impact on the photographic process is mostly inert in terms of image formation. They primarily influence the physical properties of the collodion layer or the processing steps.

Summary of the Collodion Negative Process

When the collodion, now containing cadmium bromide and ammonium iodide, is applied to a glass plate and exposed to a silver nitrate solution, the silver nitrate reacts with these halides to form the light-sensitive silver halides (AgBr and AgI). These halides are dispersed in the dried collodion layer. Upon exposure to light, these silver halides decompose, and the silver atoms aggregate to form a latent image. The image is then developed, fixed, and made permanent through photographic processing.

Photographic Qualities

• Cadmium Bromide: Adds to the contrast and spectral sensitivity of the plates. I especially like this for my negative collodion emulsions.
• Ammonium Iodide increases general sensitivity to light, which is particularly useful in lower-light conditions. I like Ammonium iodide in my negative chemistry because it helps age the collodion faster.

I should note that you must understand the safety issues with handling and using any type of chemical and in particular, wet plate collodion has several chemicals that could be harmful or even kill you if used incorrectly.

Safety & Health Risks

Working with the chemicals listed in the collodion dry plate negatives formula involves handling materials that can pose significant health and safety risks if not managed properly.

Here is an overview of the primary concerns associated with each component:

Plain USP Collodion (Nitrocellulose in Ether and Alcohol)

• Flammability: Both ether and alcohol are highly flammable, and their vapors can form explosive mixtures with air. Nitrocellulose is also flammable and can be unstable under certain conditions.
• Health Risks: Inhalation of vapors can irritate the respiratory system and may cause central nervous system effects such as dizziness or headache. Prolonged skin contact can cause irritation.

Everclear (High-Concentration Ethanol)

• Flammability: As a high-proof alcohol, Everclear is extremely flammable and poses significant fire and explosion risks, especially near open flames or sparks.
• Health Risks: Inhalation or ingestion can lead to intoxication, and prolonged exposure can cause dehydration of skin or mucous membranes.

Ethyl Ether

• Flammability and Explosiveness: Ether is highly volatile and flammable, with a tendency to form peroxides, which are explosive. It must be handled with extreme care, away from any sources of ignition.
• Health Risks: Ether vapors are anesthetic and can cause respiratory irritation, dizziness, nausea, and unconsciousness. Chronic exposure can damage the kidneys and liver.

Cadmium Bromide

• Toxicity: Cadmium compounds are highly toxic and carcinogenic. They can cause severe damage to the kidneys, lungs, and bones (itai-itai disease). Handling requires stringent controls to prevent inhalation and ingestion.
• Environmental Hazard: Cadmium is a persistent environmental pollutant that can accumulate in the food chain.

Ammonium Iodide

• Health Risks: While less hazardous than cadmium compounds, ammonium iodide can still cause irritation to the skin, eyes, and respiratory tract if not handled correctly.
• Stability Concerns: It can decompose upon exposure to light, heat, or moisture, potentially releasing iodine and ammonia gases, which are irritants.

Safety Recommendations:

• Proper Ventilation: Always use these chemicals in a well-ventilated area to avoid accumulation of harmful vapors.
• Protective Equipment: Wear appropriate protective gear, including gloves, goggles, and respiratory protection when necessary.
• Fire Safety: Have suitable fire extinguishing media on hand, such as CO2 or dry chemical extinguishers. Avoid using water, as it can spread some chemical fires.
• Spill Management: Be prepared for spills with appropriate spill containment and cleanup materials.
• Storage: Store chemicals in properly labeled, sealed containers away from light and heat. Ethyl ether should be used and stored in a way that minimizes the formation of explosive peroxides.
• Waste Disposal: Dispose of chemical waste according to local environmental regulations, especially for toxic substances like cadmium compounds.

Handling these materials with due respect to their properties and potential hazards is crucial for your safety and the safety of others in your workspace. Always follow best practices for chemical safety and environmental protection.

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Wet Plate Collodion Negative Developer

Negative Developer 1L/500ml (Plastic Storage Bottle is OK)

I use this developer when I am making wet collodion negatives. I use a separate formula when I am developing collodion dry plates.

Shelf Life 1 to 2 weeks at 20C

• Date and label my storage bottle
• Pour 500ml/250ml DH20 into a plastic storage bottle (water is the carrier)
• Add 20g/10g Ferrous Sulfate (reducer) to DH20 and pour more water to force the Ferrous Sulfate through the funnel. Dissolve by shaking the bottle.
• Pour 80ml/40ml Glacial Acetic Acid (restrainer) into the bottle
• Add 80ml/40ml Everclear (for flow) to the bottle
• Shake and dissolve.
• Top off to 1000ml/500ml with DH20
• For an 8×10 plate, you need about 50ml of developer or 35mm for whole plate.
• With negatives, we are trying to create density. We are adding a lot more acid and less iron. Good dev time is ~ 45s to 1min, but up to 3 min is ok before you start to develop the free silver and the plate starts to look like it is fogged or has a veil over it.

My wet collodion negative developer formula includes several key chemicals that interact to develop the exposed photographic plate. Let’s go through each component, its role in the development process, and the associated safety and health risks.

Distilled Water

• Purpose: Acts as the solvent in the developer formula. It dissolves the other chemicals and facilitates their interaction on the photographic plate.
• Safety and Health Risks: Distilled water is generally safe; however, its primary risk in this context is from potential contamination with other chemicals, making proper storage and handling necessary.

Ferrous Sulfate (Iron II Sulfate)

• Purpose: This is the reducing agent in the developer formula. Ferrous sulfate reduces the exposed silver ions in the silver halides (from the collodion process) to metallic silver, which forms the image.
• Safety and Health Risks: Ferrous sulfate can be irritating to the skin, eyes, and respiratory tract. Ingestion can cause nausea, vomiting, and diarrhea. It should be handled with gloves and goggles, and spills should be cleaned up promptly to avoid staining and potential slip hazards.

Glacial Acetic Acid

• Purpose: Serves as an acidifier and stop bath in the development process. It neutralizes the alkaline residues and stops the development by rapidly changing the pH, thus preventing overdevelopment of the image.
• Safety and Health Risks: Glacial acetic acid is highly concentrated and can cause severe burns to the skin and eyes. It is also corrosive to mucous membranes and the respiratory tract, capable of causing severe respiratory distress if inhaled. Use with adequate ventilation, and always wear protective clothing, including gloves and eye protection. Acetic acid should be handled with extreme care, and neutralizing agents should be readily available in case of spills.

Everclear (High-Concentration Ethanol)

• Purpose: Acts as a solvent in the developer. It helps the developer penetrate the collodion layer more effectively and can influence drying time and grain quality.
• Safety and Health Risks: As previously discussed, Everclear is extremely flammable and poses significant fire and explosion risks. Inhalation or ingestion in large amounts can lead to alcohol poisoning; vapors can irritate the eyes and respiratory system. Proper handling includes using the chemical away from open flames and sources of sparks, and using it in a well-ventilated area.

Safety Precautions and Recommendations:

• Ventilation: Use all chemicals in a well-ventilated area to minimize inhalation risks.
• Protective Equipment: Gloves, goggles, and possibly a face shield should be worn, especially when handling acetic acid and ferrous sulfate.
• First Aid Measures: Have appropriate first aid measures and materials ready, including eye wash stations and neutralizing agents for acids.
• Chemical Storage: Store chemicals separately and in clearly labeled containers to avoid accidental mixing and contamination.
• Spill Management and Fire Safety: Be prepared for chemical spills and fires by having suitable clean-up materials and fire extinguishers readily available.

Handling these chemicals with knowledge of their functions and risks ensures both effective photographic results and safety in the darkroom.

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Wet Plate Collodion Negative Re-Developer

Redeveloper Solution (1000ml/500ml)

I use this re-developer for my wet collodion negatives and I use a slightly different version for my collodion dry plate negatives. The only difference between the two formulas is that I use 15g of citric acid in the collodion dry plate developer vs. 8g as noted here. The other variation for wet collodion negatives is I use a weak solution of iodine on the plate before using the re-developer solution to help re-halogenate the plate before development.

Shelf Life 1 to 2 weeks at 20C

• Start with 1000ml/500ml DH20 in storage bottle. Plastic is ok.
• 4g/2g Pyrogallic Acid
• 8g/4g Citric Acid
• Use about 80ml (whole plate or 5×7), 100ml (8×10)
• To use, add 10 drops of 10% AgN03 (Part C) per plate. (density builder)
• Pyrogallic Acid is used as a reducer/strainer to redevelop negatives. Always wear gloves when using this compound and never get airborne or breath in particles or fumes. Always wear a mask.

Here’s an explanation of each chemical’s role in the re-development process and the associated health and safety concerns:

Distilled Water

• Purpose: Serves as the solvent for the other chemicals in the re-developer formula, facilitating the uniform application and reaction on the photographic plate.
• Safety and Health Risks: Distilled water itself poses no significant health risk, though care should be taken to ensure it remains clean and free from contamination by other chemicals.

Pyrogallic Acid (Pyrogallol)

• Purpose: Pyrogallic acid is a powerful developing agent used in photographic processes. In the context of re-development, it reduces exposed but undeveloped silver halides on the plate to metallic silver, enhancing the density and detail of the image. It is especially effective in bringing out details in shadow areas that may have been underdeveloped in the initial processing.
• Safety and Health Risks: Pyrogallic acid is toxic if ingested, inhaled, or absorbed through the skin. It is also an irritant to the skin, eyes, and respiratory system. When exposed to air, it can oxidize rapidly, becoming potentially more hazardous. Handling pyrogallic acid requires gloves, protective eyewear, and ideally, a mask to prevent inhalation of any dust. Work in a well-ventilated area to avoid accumulation of any vapors. Due to its toxicity and potential for causing stains and burns, spills should be managed carefully.

Citric Acid

• Purpose: Citric acid is used to control the pH of the developer solution. It acts as a mild preservative and can chelate (bind) metal ions, which helps in maintaining the stability of the developing solution and prevents streaking or uneven development. Its inclusion helps to achieve finer control over the redevelopment process, influencing contrast and the overall tonality of the image.
• Safety and Health Risks: Citric acid is generally less hazardous than pyrogallic acid but can still cause irritation to the skin and eyes. If inhaled in powder form, it can irritate the respiratory tract. As with many acids, handling citric acid should involve wearing gloves and goggles to prevent skin and eye contact. Although it is not as toxic or hazardous as many other chemicals used in photographic processes, care should still be taken to handle it properly.

General Safety Recommendations for Handling These Chemicals

• Protective Equipment: Use gloves, goggles, and masks as necessary to protect against chemical exposure.
• Ventilation: Ensure that all handling and mixing of chemicals, particularly those involving pyrogallic acid, occur in a well-ventilated area.
• Spill Response: Have appropriate materials and procedures ready for dealing with spills, particularly for the more toxic pyrogallic acid.
• Storage: Store chemicals in clearly labeled, sealed containers in a cool, dry, and dark place to prevent degradation and accidental misuse.

By understanding each chemical’s role and the associated risks, you can take appropriate precautions to safely use these substances in your photographic re-development process.

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The Journey from Calotyope Paper Negatives to Collodion Dry Plate Negatives

1830s Fox Talbot’s Calotype Paper Negative Process

Inventor: William Henry Fox Talbot, an English scientist and photography pioneer.

Process: Known as the Calotype or Talbotype process.

Key Features:

It was the first negative-to-positive process, allowing multiple copies from a single negative.

Used paper sheets coated with silver chloride, which darkened when exposed to light.

Significance: This process laid the groundwork for modern photographic techniques.

1839 Daguerreotype

Inventor: Louis Daguerre, a French artist and photographer.

Process: Almost simultaneous with Talbot’s invention, but distinct.

Key Features:

Produced a single, highly detailed image on a silvered copper plate.

Was a positive-only process, meaning no negatives were created.

Impact: Despite its limitations, the Daguerreotype was immensely popular due to its detail and clarity.

1851 Wet Plate Collodion Process

Inventor: Frederick Scott Archer, an English sculptor and photographer.

Process: Known as the Collodion process.

Key Features:

Used a glass plate coated with a mixture of ether, alcohol, and collodion, then sensitized with silver nitrate.

Required the photographic plate to be exposed and developed while still wet.

Advantages: Higher quality and shorter exposure times than the Calotype.

Challenges: The need for immediate processing made it impractical for some types of photography.

1850s Ambrotype and Tintype

Development: Variations of the wet collodion process.

Ambrotype:

Used a glass plate negative with a dark backing, creating a positive image.

Tintype:

Used a thin sheet of iron instead of glass.

Popularity: These processes were cheaper and faster, making photography more accessible.

1860s Collodion Dry Plate Process

Advancement: Addressed the main limitation of the wet collodion process – the need for immediate development.

Process:

A sensitized collodion plate was washed to remove the free silver and preserved with a tannin so it could be dried, exposed, and developed at a later time.

Significance:

The collodion dry plate process was an intermediary step between the wet collodion process and the silver gelatin dry plate process. It represented photographers’ early efforts to make the photographic process more practical and portable, leading up to the significant advancements by Maddox.

This progression from Fox Talbot’s negative process to the collodion dry plate process revolutionized photography, making it more versatile and accessible. Each step brought technical improvements that expanded the possibilities of capturing images, ultimately leading to the diverse photographic practices we have today.

The exact timeline for the creation of collodion dry plates is somewhat less clear-cut than for other photographic processes, as it was more of an evolutionary development rather than a single invention attributed to a specific date or inventor.

After the introduction of the wet collodion process by Frederick Scott Archer in 1851, photographers began experimenting to overcome its limitations, particularly the need for immediate processing. This led to various adaptations over the next couple of decades, with photographers trying different ways to prepare and use collodion plates that didn’t require them to be wet at the time of exposure.

By the 1860s, there were reports of photographers using collodion dry plates, but these were not standardized and were often prepared by individual photographers according to their own methods. These dry plates didn’t gain widespread popularity due to their lower sensitivity compared to wet plates and the more complicated preparation process.

Thomas Sutton (1819-1875) published The Collodion Process Wet & Dry in 1862, which is still valid and useable today. So, we know based on this that collodion dry plates were in practice at that time, and for the book to have been written, it is only logical to believe the details were worked out well before 1862.

It wasn’t until Richard Leach Maddox introduced the silver gelatin dry plate process in 1871 that a significant shift occurred, moving away from collodion-based processes. Maddox’s process, with its greater convenience and improved sensitivity, quickly overshadowed earlier dry plate techniques and set the stage for modern film photography.

One of the most important things that I never see addressed is how the emulsions made with collodion versus silver gelatin produces a much different aesthetic. Art isn’t and shouldn’t be defined by a single factor such as convenience.

I believe the extra effort and mastery of the collodion chemistry process is worth the effort based on the prints that I am able to make from these negatives.

1880s Silver Gelatin Dry Plates

The Evolution from Wet Plate to Dry Plate: A Milestone in Photographic Technology

The history of photography is marked by rapid technological advancements, each fundamentally altering how images were captured, developed, and viewed. One of the most significant transitions was the shift from the wet plate collodion process to the dry plate technique, notably the silver gelatin process. This transition not only marked a technological leap but also changed photography’s practical and artistic landscape.

The Era of Wet Plate Collodion

Introduced by Frederick Scott Archer in 1851, the wet plate collodion process became the backbone of photographic art and science during the mid-19th century. This process involved coating a glass plate with collodion, sensitizing it in a bath of silver nitrate, and then exposing and developing it while still wet. The method was renowned for its ability to produce highly detailed images and was widely adopted for its superior quality compared to the earlier daguerreotype and calotype processes.

However, the wet plate process had significant drawbacks. The need for the plates to remain wet during exposure and development demanded that photographers either work quickly or have immediate access to a portable darkroom, greatly limiting the scope and spontaneity of photography.

A dry plate version of the collodion process, known as the collodion dry plate or the dry collodion process, emerged as an alternative to the wet plate collodion process. Despite this innovation, the collodion dry plate did not achieve the same popularity or widespread adoption as the later silver gelatin dry plates.

Several factors contributed to this disparity:

Complexity and Sensitivity: The dry collodion plates were more complex to prepare and less sensitive to light compared to their wet plate counterparts. The process involved coating a glass plate with collodion, sensitizing it, and then treating it with a preservative before it could be dried and stored. This preservative often reduced the plate’s sensitivity, resulting in longer exposure times when the plate was finally used. This was less practical compared to the silver gelatin plates, which were more sensitive and required shorter exposure times.

In practical terms, a typical exposure time for my collodion dry plates is between 7 and 10 minutes versus 1 to 10 seconds for wet plate collodion.

Image Quality and Handling: Although dry collodion plates offered the advantage of being usable days or even weeks after preparation, they generally produced images that were not as fine in detail or as sharp as those produced by wet plates. The preparation of dry collodion plates also had to be very precise to avoid flaws and inconsistencies in the photographic results.

Commercial Viability and Ease of Use: The introduction of silver gelatin dry plates by Dr. Richard L. Maddox and their subsequent refinement offered a more user-friendly and commercially viable option. These plates could be mass-produced with consistent quality and sensitivity, making them more attractive to both amateur and professional photographers.

Storage and Longevity: Silver gelatin plates were more robust in terms of storage and less susceptible to temperature changes and humidity, which could affect the collodion plates. This made silver gelatin plates more suitable for a wider range of environments and conditions.

Technological Advancements: The gelatin used in silver gelatin plates provided a more stable and adaptable medium for light-sensitive materials, allowing for further speed and sensitivity improvements through emulsion technology advances. This adaptability led to continuous improvements in the silver gelatin process, which outpaced developments in the collodion-based alternatives.

Overall, while the dry collodion process represented an important step in the evolution of photographic technologies, allowing for some degree of pre-preparation and portability, it was ultimately eclipsed by the superior characteristics of the silver gelatin dry plate, which better met the needs of photographers for ease of use, speed, and image quality. This set the stage for the next evolution in photography, leading towards the development of modern film.

The Advent of Silver Gelatin Dry Plate Photography

The search for a more convenient method led to experiments and developments in dry plate photography, where plates could be prepared in advance, used when needed, and developed later. The breakthrough came in the 1870s, primarily through the work of Dr. Richard L. Maddox who in 1871 introduced a gelatin dry plate process. Maddox’s innovation replaced collodion with gelatin as the binder for the light-sensitive silver bromide crystals, allowing the plates to be coated and stored for a period before use.

The dry plate technology was further refined and popularized by Charles Bennett in the late 1870s, who developed a method to make the gelatin emulsion even more sensitive to light, reducing exposure times dramatically. This enhancement made dry plates vastly more convenient than their wet plate predecessors.

Reasons for the Shift

The transition from wet to dry plates was driven by several key factors:

Convenience: Silver gelatin dry plates could be commercially produced, sold, and used as needed. Photographers no longer needed to prepare their plates and chemicals, which also reduced the equipment they had to carry.

Sensitivity and Speed: The increased sensitivity of silver gelatin dry plates reduced exposure times from minutes to seconds, opening up new possibilities for capturing motion and reducing the blur in images of living subjects.

Storage and Transport: Unlike wet plates, dry plates did not require immediate processing, making them ideal for fieldwork and allowing photographers to work in various conditions and locations.

Quality and Reproducibility: Silver gelatin dry plates maintained the high image quality of the wet plate process but offered greater consistency and ease of use.

During the 19th century, photography was a burgeoning art and science, capturing the imagination of both the general public and enthusiasts who were photographers themselves. One of the main drivers of this fascination was portraiture, which played a significant role in shaping photographic practices and technological developments of the era. The issue of long exposure times was closely tied to the popularity of portraits, influencing both the demand for technological improvements and the subjects’ experience during the photographic process.

Importance of Reducing Long Exposure Times

Practical Challenges: In the early days of photography, particularly during the era of daguerreotypes and the initial phase of wet plate collodion processes, exposure times could last from several seconds to several minutes. This required subjects to remain absolutely still to avoid blurring the image. Long exposure times were especially challenging when photographing children, animals, or scenes with movement.

Comfort of the Subject: Sitting still for long periods was uncomfortable and impractical for subjects, often requiring the use of headrests or other supports to maintain a pose. Shorter exposure times offered a more comfortable and convenient experience, making the photographic process less daunting and more accessible to a wider audience.

Commercial Viability: Photographers were keenly interested in reducing exposure times to increase the throughput of their studios. Faster exposures allowed more clients to be photographed in a day, thus increasing profitability. It also made photography sessions more appealing to potential customers.

Portraits as the Main Driver in 19th Century Photography

Personal and Social Significance: Portraits were immensely popular because they provided a means of preserving the likeness of individuals in an era before widespread visual media. They were cherished as family heirlooms, mementos of loved ones, and as a form of social status. The ability to capture one’s image was no longer restricted to the time-consuming and expensive medium of painted portraits.

Technological Innovations Inspired by Portraiture: The demand for portrait photography drove many innovations designed to improve image quality, reduce costs, and decrease exposure times. Developments like the tintype and carte de visite, which were small, easily reproducible, and inexpensive, spread rapidly because they catered to the public’s desire for portraits.

Artistic Expression: Photography as an artistic medium grew in part from the ability to capture human expressions and the human condition. Portraits were not only a commercial commodity but also an artistic pursuit, allowing photographers to explore lighting, composition, and eventually, more candid styles of capturing human emotion and personality.

Widening Access to Photography: Portraits were crucial in democratizing photography. They were more affordable and accessible compared to traditional painted portraits, allowing middle and working-class individuals to have their likenesses captured and preserved, a privilege once reserved only for the wealthy.

In summary, the fascination with portraiture drove much of the development and popularization of 19th-century photography. Portraits provided personal, social, and artistic value, serving as a key motivator for both technical innovations and the widespread adoption of photography. Reducing long exposure times was crucial in making photography a viable and popular medium, enhancing both the comfort of the subject and the operational efficiency of photographers. This synergy between technological advancement and social demand shaped the trajectory of photography, making it an indispensable part of modern culture.

Impact and Legacy

The adoption of the dry plate was swift and global, profoundly impacting both amateur and professional photography. It set the stage for the introduction of film at the end of the 19th century by George Eastman, who commercialized flexible roll film and later introduced the Kodak camera in 1888, which used a paper-based film. This further democratized photography, making it accessible to the general public and not just skilled artisans.

Conclusion

The transition from wet plate collodion to silver gelatin dry plates represents a pivotal moment in photographic technology. It not only simplified the photographic process but also expanded the creative and commercial potential of photography, paving the way for modern photographic practices. This period of innovation exemplifies how technological advancements can redefine art, opening new horizons for artistic expression and practical application.

Silver Gelatin Dry Plate Emulsion Formula

A typical silver gelatin dry plate emulsion formula from the late 1800s, following Dr. Richard Leach Maddox’s invention, would have included several key components.

Here’s a basic outline of such a formula:

Silver Nitrate Solution:

• Silver Nitrate (AgNO₃): Acts as the light-sensitive component.
• Distilled Water: Used to dissolve the silver nitrate.

Gelatin Solution:

• Gelatin: Serves as the binder for the emulsion, creating a stable layer on the glass plate.
• Distilled Water: Used to dissolve and swell the gelatin.

Halide Solution:

• Potassium Bromide (KBr) or Ammonium Bromide (NH₄Br): These halides react with silver nitrate to form silver bromide, a light-sensitive compound.
• Distilled Water: Used to dissolve the halides.

Sensitization:

• Mixing the silver nitrate solution with the halide solution in the presence of the gelatin to form silver halide crystals within the gelatin matrix.

Ripening:

• The emulsion is typically heated gently to encourage the growth of silver halide crystals to a desired size, which affects the sensitivity and grain of the emulsion.

Coating:

• The emulsion is then spread evenly over glass plates and allowed to set and dry.

Additional Ingredients (Optional):

• Certain additives might be included to adjust the characteristics of the emulsion, such as:
  • Sensitizers to extend the emulsion’s sensitivity to different parts of the light spectrum.
  • Hardeners to improve the durability of the gelatin layer.
  • Preservatives to extend the shelf life of the emulsion.

Notes:

• The exact proportions and additional components might vary based on the desired sensitivity, contrast, and grain of the final photographic plate.
• This formula represents a basic approach from the late 19th century and was refined and modified by individual photographers and manufacturers over time, eventually moving from an ordinary emulsion (color blind) in the 1870s and panchromatic in the 1890s (reproduces all colors correctly).

Even though panchromatic formulas existing in the early 1870s, they were not adopted or used my many photographers for several decades later.

Silver gelatin dry plates started off being only sensitive to blue light (color blind) and eventually became orthochromatic (not sensitive to reds, but everything else).

The first panchromatic emulsion, which is sensitive to all colors of light in the visible spectrum, was invented by Hermann Wilhelm Vogel in 1873. Vogel, a German photochemist, discovered that by adding certain dyes to photographic emulsions, their sensitivity could be extended beyond the blue and ultraviolet spectrum, which was the primary limitation of the photographic materials available at the time.

Before Vogel’s discovery, photographic emulsions were predominantly orthochromatic, meaning they were sensitive mainly to blue and green light, but not to red light. This limitation led to unbalanced representations of colors when converted to grayscale, particularly underexposing reds and overexposing blues.

By adding dyes that sensitized the emulsion to the broader spectrum of visible light, Vogel’s panchromatic emulsion allowed for a more accurate and balanced rendering of scenes in black and white photography.