Formulary

I use a variety of chemistry and formulas in my large and ultra large format fine art work.

Wet Plate Collodion Chemistry

Wet Plate Collodion 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 you hand and work it with a glass rod and break it up until it is fully dissolved. (Don’t get this airborne and breath this because it can kill you!!!)
  • Place the small beaker on the scale and 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 collodion emulsion faster (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 go with NH4I and not CdI; that’s more stable and will be better for contrast. NH4I and CdBr are the winning tickets for wet or dry negatives in my opinion. You can try a 50/50 of NH4I/CdI if you want to experiment and compare 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 Photographic 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.

Wet Plate Collodion Negative Developer

NEGATIVE DEVELOPER 1L/500ml (PLASTIC BOTTLE IS OK)

I use this developer when I am making wet collodion negatives. I use a separate formula for 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.

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.

Soft Working Paper Developers

I use a variety of soft-working developers for my paper negatives. The goal is to create a soft negative that has good detail in the highlights and shadows that is lower in contrast than a normal negative to allow for the addition of density via pencil and charcoal work on the back of the negative.

Ansco 120 Soft-Working Paper Developer

  • Water at 52C 750ml
  • Metol 12.3g
  • Sodium sulfite 36g
  • Sodium carbonate (mono) 36g
  • Potassium bromide 1.8g
  • Water to make 1 liter

Dilute 1:1 or more as desired.
Warmer tones may be obtained by adding more KBr (up to 4g)

I typically use this formula to develop my Ilford Warmtone or Ilford Classic Matt paper negatives.

Gevaert G.253 Soft Portrait Paper Developer

  • Water at 52C 750ml
  • Metol 3g
  • Sodium sulfite 20g
  • Sodium carbonate (mono) 23g
  • Potassium bromide (KBr) 1g
  • Water to make 1 liter

Use undiluted (less soft), 1:1, or more for softer tones.
Warmer tones may be obtained by adding more KBr (up to 4g)

I use this as my print-developing formula and add extra potassium bromide to warm up the Ilford Warmtone Semi-Matt paper.

Agfa 105 Low-Contrast Developer

  • Water at 52C 750ml
  • Metol 3g
  • Sodium sulfite 15g
  • Potassium carbonate 15g
  • Potassium bromide 0.4g
  • Water to make 1 liter

Use undiluted with a normal 1.5 to 2 min development time.

Try this as an alternative to the Ansco 120 formula above and see which one you like best. Review the proportion of each chemical and compare the two formulas. Also, use the chemistry notes below to help understand the role of each chemistry element.

Paper Developer Chemistry Notes

Water at 52°C: Water is the solvent where all the chemicals are dissolved. The water’s temperature affects the developer’s activity; warmer temperatures (like 52°C) tend to increase the activity, resulting in faster development.

Metol: Metol is an organic compound used as a developing agent. It reduces the exposed silver halide crystals in the film or paper to metallic silver, creating the image. Metol is known for its fine grain and good image detail.

Sodium Sulfite: Sodium sulfite acts as a preservative, preventing the oxidation of Metol and other developing agents in the solution. It also helps to maintain the necessary pH and can influence the image’s contrast and grain.

Sodium Carbonate, Monohydrate: Sodium carbonate is an accelerator or activator. It increases the pH of the developer, making the development process faster. This results in greater sensitivity to the film or paper, affecting the contrast and speed of development.

Potassium Bromide: Potassium bromide (KBr) is a restrainer or anti-fogging agent. It helps to control the development process, preventing the developer from acting on unexposed silver halide crystals. This results in clearer whites and helps to maintain image sharpness and fine grain.

Water to make 1 liter: Additional water is added to bring the total volume of the developer up to 1 liter. This ensures the proper concentration and balance of the chemicals.

Combining these chemicals in the specified proportions creates a developer solution used in photographic processing, influencing the final image’s development speed, image contrast, grain, and overall quality.

Farmers Reducer

Farmer’s Reducer is a darkroom staple for anyone wishing to make expressive prints. This little trick helps us paint with light in our silver prints, but it is also very useful for reducing silver in our negatives. I use a modified version on my collodion wet and dry plate negatives in scenarios where I have dark areas (oftentimes dark artifacts) that show up white on the prints. By reducing them with Farmers Reducer, I can typically make those blemishes go away. I also use it on my negatives to add or strengthen shadow areas that I am not able to address during the printing process.

The Classic Formula for Prints

Stock Solution A:

  • Potassium ferricyanide 60g
  • Potassium bromide 30g
  • Distilled water to make 250ml

Stock Solution B:

  • Sodium thiosulfate 120g
  • Distilled water to make 750ml

The two solutions are mixed in varying dilutions to meet your specific use case. Once mixed together, the combined solution exhausts very quickly, typically 10 to 15 minutes, which is noted by the change in color.

Usage Tips

Overall reduction, mix 7.5 ml of Solution A with 180.0 ml of Solution B, and add 1500.0 ml of water. The amount of Solution A may be increased or decreased to control the time of reduction.

Local bleaching use the same proportions of A and B as for overall reduction. Increasing the amount of ferricyanide solution will increase the rate of reduction.

Alternately, dissolve approximately ¼ teaspoon of ferricyanide in 200.0 ml of water. If you are working on lighter tones you will want to start with less ferricyanide in solution as the bleach works rapidly on light areas; you can always add more ferricyanide to speed things up.

Spot reduction, mix 1 part A to 2 parts B without adding water.

If you need more guidance on how to use Farmers Reducer, refer to Chapter 11 in the Darkroom Cookbook by Steve Anchell.

This formula has been a staple in photographic processing, particularly useful for correcting overexposure or development errors in film photography. Its usage reflects the intricate chemistry involved in traditional photographic processes. Thank you for correcting the information, ensuring accuracy in the description of Farmer’s Reducer.

The history of Farmer’s Reducer dates back to the 19th century. It was named after the British photographer and chemist, James Farmer, who is credited with its invention. Farmer’s work was pivotal during the early days of photography, a time when photographic processes and chemical formulations were being actively explored and refined. The invention of Farmer’s Reducer was particularly significant as it provided photographers with a means to correct overexposed or overdeveloped photographic prints, a common problem in the early days of photography due to the lack of precise exposure control.

Understanding The Chemistry

Potassium Ferricyanide (K₃[Fe(CN)₆]): This compound acts as an oxidizing agent. It oxidizes the metallic silver in the overexposed areas of the photographic print or negative to silver ion. The oxidized silver then becomes soluble in the presence of the fixer (sodium thiosulfate).

Sodium Thiosulfate (Na₂S₂O₃), commonly known as ‘hypo’: Sodium thiosulfate is a fixing agent. After the metallic silver is oxidized to silver ion by potassium ferricyanide, sodium thiosulfate reacts with these silver ions to form soluble silver thiosulfate complexes, which are then washed away, reducing the density of the image.

Potassium Bromide (KBr): Potassium bromide acts as a restrainer or an anti-fogging agent. It helps to control the reduction process initiated by potassium ferricyanide, ensuring that it is more selective and consistent. It prevents the reducer from attacking unexposed silver halide crystals, which would cause fogging (undesired overall density) on the photographic material.

My Custom Formula & Use

I keep a 10% solution of potassium ferricyanide mixed up and stored in a 200ml brown dropper bottle in the darkroom at all times.

I do the same for potassium bromide. I mix it as a 5% solution.

Then, when I need to use the reducer on a collodion glass plate negative or a silver print, I mix a 250ml 25% sodium thiosulfate (hypo) solution on demand.

In a small 100ml glass beaker or shot glass, I pour in 50ml of hypo and then 4 drops of 10% potassium ferricyanide stir with a glass rod, and use it immediately. It will only last 10 to 20 minutes, and you will notice a color change indicating its end of life.

If I am going to work on a print, I use the same method as stated above for my negatives, but I also add 2 drops of potassium bromide.

Negative Retouching Paste

For my collodion wet and dry plate negatives, there are times when I need or want to add density to help correct blemishes or add light to the scene.

I use a sheet of Canson Vidalon Vellum paper on the back side of the plate and shade in the areas with pencils and charcoal. I blend the areas with an artist blending paper stump.

The registration needs to be perfect, so I mix up some organic paste that doesn’t add density to the negative and is easily removed from the black of the plate with alcohol if and when I want to remove the retouching mask.

I cut the vellum paper to the exact size of the plate and then add a small dab of paste to all four corners of the plate with a precision Q-tip.

I use gum arabic (dry powder), glycerin, and Everclear alcohol to make the organic paste. I mix up the three elements in a small paper mixing cup and stir with a wooden coffee stirring stick.