What is the primary purpose of using a chemical fixer in film processing?

The primary purpose of using a chemical fixer in film processing is to dissolve unused silver halide salts. After the film has been exposed to radiation and developed, there are still unexposed silver halide crystals that could cause fogging or deterioration of the image over time if they are not removed. The fixer works by chemically transforming these unexposed crystals into a soluble form that can then be washed away. This step is crucial because it ensures that the final image is clear and stable, preserving both the quality and longevity of the film.

While enhancing image clarity is important, this is more directly a function of the developing solution rather than the fixer. Increasing film sensitivity is achieved through other means during the film production process and does not directly relate to the role of the fixer. Maintaining film integrity is a broader concept that encompasses more than just the action of fixing; it includes various aspects of film processing and handling. Thus, the fixer’s specific role in removing unexposed silver halide salts is what makes it essential in creating a high-quality, lasting image.