What happens to the unreduced silver halide crystals during the fixing process?

During the fixing process of radiographic film, the unreduced silver halide crystals are removed. In the context of film processing, these crystals have not been exposed to light or radiation and thus do not contribute to the image on the film. The fixer solution, which contains chemicals such as thiosulfate, dissolves these unexposed silver halide crystals, ensuring that they do not affect the quality of the final image.

The removal of these crystals is a crucial step in achieving a stable and processed radiograph, as it prevents any unwanted exposure from creating fog or reducing the contrast of the image. Once this process is completed, only the reduced silver, which corresponds to the exposed areas of the film and has developed into a black metallic form, remains. This allows for a clear representation of the structures being imaged. After fixing, the film can be safely viewed under normal light, as there are no remaining unexposed silver halide crystals that would otherwise darken or obscure the image.