fixing

photography

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June 26, 2026

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Fixing is a crucial step in traditional photography that makes a latent image permanent. After the film is exposed and developed, the fixing bath, typically containing sodium or ammonium thiosulfate, dissolves the remaining light-sensitive silver halide crystals. This process removes the milky appearance of the film, making the image visible and stable. The fixer also contains an acid to stop development and a hardening agent to protect the film's gelatin layer. This chemical treatment ensures the photograph can be preserved and viewed without further degradation.12

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history of photography
Daguerreotype
…1837 Daguerre was able to fix the image permanently by using a solution of table salt to dissolve the unexposed silver iodide. That year he produced a photograph of his studio on a silvered copper plate, a photograph that was remarkable for its fidelity and detail. Also that year, Niépce’s…
Read More
…1837 Daguerre was able to fix the image permanently by using a solution of table salt to dissolve the unexposed silver iodide. That year he produced a photograph of his studio on a silvered copper plate, a photograph that was remarkable for its fidelity and detail. Also that year, Niépce’s…
Read More

technology of photography
Fixing
The fixing bath contains a chemical (sodium or ammonium thiosulfate) that converts the silver halide into soluble, complex silver salts that dissolve in the fixer. During this process the film loses its original silver halide milkiness overlaying the image and becomes clear. The fixer…
Read More
The fixing bath contains a chemical (sodium or ammonium thiosulfate) that converts the silver halide into soluble, complex silver salts that dissolve in the fixer. During this process the film loses its original silver halide milkiness overlaying the image and becomes clear. The fixer…
Read More