The Complete Guide to Autochrome: The First Color Photography Process

Lost in Russia
6 min readJun 1, 2023

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The Autochrome process was the first widely-used color photography method, invented by the Lumière brothers, Auguste and Louis, in 1907. This groundbreaking technique utilized a glass plate coated with dyed potato starch and a color-sensitive emulsion to create stunning color images. The Autochrome process remained popular until the 1930s when more advanced methods superseded it. In this comprehensive guide, we will explore the step-by-step process of creating Autochrome plates and delve into the history and significance of this revolutionary technique.

Historical Background

The Lumière brothers, Auguste and Louis, were pioneers in the field of photography and filmmaking. Their invention of the Autochrome process in 1907 marked a significant advancement in color photography. The brothers built upon the work of previous inventors, such as Louis Ducos du Hauron, John Joly, and James William McDonough, who had experimented with color separation techniques and screen plates to produce color images on paper.

The Autochrome process quickly gained popularity for its aesthetic appeal and its ability to produce natural, vibrant colors. It remained the principal color photography process in use until the advent of subtractive color film in the mid-1930s.

Ingredients and Tools

To create an Autochrome plate, you’ll need the following ingredients and tools:

· Glass plate: A clean and smooth glass plate to serve as the base for the Autochrome plate.

· Potato starch: Used to create the color filter layer.

· Dyes: Red, green, and blue dyes to color the potato starch particles.

· Gelatin: Used as a binder for the potato starch and dyes.

· Silver bromide emulsion: Sensitive to light and forms the light-sensitive layer.

· Chemicals: Various chemicals for developing, fixing, and washing the plate.

· Darkroom equipment: Darkroom, trays, thermometer, stirring rod, measuring beakers, etc.

· Light source: A controlled light source for exposing the plate.

Step-by-Step Process (Overview)

1. Clean the glass plate thoroughly to ensure a smooth surface.

2. Prepare the potato starch solution by mixing it with water and heating it to create a viscous paste.

3. Divide the potato starch paste into three portions and add the red, green, and blue dyes separately. Stir each mixture thoroughly to create colored starch particles.

4. Spread a thin layer of gelatin on the glass plate to act as an adhesive for the starch particles.

5. Sprinkle the colored starch particles evenly onto the gelatin-coated plate. These particles will form the color filter layer.

6. Allow the starch particles to dry and set on the plate.

7. Apply a layer of the silver bromide emulsion on top of the color filter layer. This emulsion will capture the light and form the image.

8. Dry the plate in a controlled environment, avoiding dust or contamination.

9. Load the plate into a light-tight holder or camera for exposure.

10. Expose the plate to a controlled light source, capturing the desired image.

11. Develop the exposed plate using the appropriate chemicals and techniques.

12. Fix the developed image to make it permanent and remove any unexposed silver salts.

13. Wash the plate thoroughly to remove any residual chemicals.

14. Allow the plate to dry completely before handling or further processing.

Step 1: Cleaning the Glass Plate

Before you begin the Autochrome process, it’s essential to start with a clean and smooth glass plate. Any dirt, dust, or imperfections on the glass surface can affect the final image quality. To clean the glass plate, use a lint-free cloth and a glass cleaner or isopropyl alcohol. Ensure that the plate is completely dry before moving on to the next step.

Step 2: Preparing the Potato Starch Solution

To create the color filter layer, you’ll need to prepare a potato starch solution. Begin by mixing potato starch with water in a container, then heat the mixture until it forms a viscous paste. Stir the solution continuously to ensure a smooth and consistent texture.

Step 3: Dividing and Coloring the Potato Starch Paste

Once the potato starch paste is ready, divide it into three equal portions. Add red, green, and blue dyes to each portion, stirring thoroughly to create colored starch particles. These colored particles will form the basis of the color filter layer in the Autochrome plate.

Step 4: Spreading the Gelatin Layer

Apply a thin layer of gelatin to the clean glass plate. This layer acts as an adhesive, helping the colored starch particles adhere to the glass surface. Ensure that the gelatin layer is smooth and even to avoid any imperfections in the final image.

Step 5: Sprinkling the Colored Starch Particles

Sprinkle the colored starch particles evenly onto the gelatin-coated glass plate. It’s crucial to achieve a uniform distribution of the particles to create an accurate color filter layer. This layer will ultimately determine the quality and vibrancy of the final Autochrome image.

Step 6: Drying and Setting the Starch Particles

Allow the starch particles to dry and set on the glass plate. This step may take some time, depending on the environmental conditions. It’s essential to ensure that the particles are fully dry before moving on to the next step, as any moisture can affect the final image quality.

Step 7: Applying the Silver Bromide Emulsion

Once the color filter layer is dry, apply a layer of the silver bromide emulsion on top of the starch particles. This light-sensitive emulsion will capture the light and form the image on the Autochrome plate. Ensure that the emulsion layer is smooth and even, as any imperfections can affect the final image quality.

Step 8: Drying the Plate

Dry the Autochrome plate in a controlled environment, avoiding any dust or contamination. This step may take several hours or even longer, depending on the conditions. It’s crucial to ensure that the plate is completely dry before moving on to the next step.

Step 9: Loading the Plate for Exposure

Load the dried Autochrome plate into a light-tight holder or camera, ensuring that the glass side faces the lens. This arrangement allows the light to pass through the color filter layer before reaching the emulsion, creating a color image on the plate.

Step 10: Exposing the Plate

Expose the Autochrome plate to a controlled light source, capturing the desired image. The exposure time will vary depending on the sensitivity of the emulsion and the lighting conditions. It’s essential to use a consistent light source and exposure time to achieve accurate and consistent results.

Step 11: Developing the Plate

Develop the exposed Autochrome plate using the appropriate chemicals and techniques. This process involves several steps, including developing, fixing, and washing the plate. It’s crucial to follow the correct procedures and use the right chemicals to ensure a successful outcome.

Step 12: Fixing the Image

After development, fix the image on the Autochrome plate to make it permanent. This step involves removing any unexposed silver salts from the emulsion, ensuring that the image remains stable and doesn’t fade over time.

Step 13: Washing the Plate

Wash the Autochrome plate thoroughly to remove any residual chemicals from the developing and fixing processes. This step is crucial to ensure the long-term stability and quality of the final image.

Step 14: Drying and Handling the Finished Plate

Allow the Autochrome plate to dry completely before handling or further processing. This step may take several hours or longer, depending on the environmental conditions. It’s important to handle the plate carefully to avoid any damage or contamination.

Once the plate is dry, you can apply a protective topcoat, such as an acrylic varnish, to preserve the image. You may also choose to mount the plate against another piece of glass for display or storage purposes.

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