Final answer:
In radiography, the fixer stabilizes the image on the film by removing undeveloped crystals, making the image durable and insensitive to light.
Step-by-step explanation:
The function of the fixer in radiography is to stabilize the image on the radiographic film after it has been exposed to radiation. The fixer works by removing any unexposed or undeveloped silver halide crystals from the film emulsion, which effectively fixes the image, making it insensitive to further light exposure. This is crucial as it ensures that once the radiographic film is developed, the image will not be ruined by accidental light exposure. The fixer is an essential part of the film processing after radiographic exposure as outlined in modern medical imaging techniques for ensuring quality and durability of the captured images.