What can be stated about the relationship between exposure time and the darkness of a radiograph?

The relationship between exposure time and the darkness of a radiograph is directly proportional; as exposure time increases, the darkness or density of the radiograph also increases. When the film or sensor is exposed to radiation for a longer period, more radiation interacts with the film, allowing more photons to reach the film emulsion. This increased interaction leads to greater darkening of the film. Therefore, if more exposure time is given, the darker the resultant image tends to be.

Radiography relies on the principle that increased radiation exposure causes more silver halide crystals in the film emulsion to be converted to metallic silver, resulting in a darker appearance on the developed film. This is why longer exposure times are associated with darker images, reinforcing the understanding of proper exposure parameters in radiographic practice.