Which technical error in radiography will lead to increased film density?

In radiography, increased film density occurs when the film takes on a darker appearance due to the amount of radiation exposure it receives. When the focal-film distance is too short, the x-rays reach the film with higher intensity because they travel a shorter distance. This increased intensity results in more energy being deposited on the film, leading to a darker image.

In contrast, other factors like insufficient mAs settings or low development temperature would actually reduce film density, resulting in a lighter image. Specifically, if the mAs settings are too low, the amount of radiation reaching the film is insufficient, producing a film that is not densely exposed. Similarly, if the temperature during development is too low, it would hinder the chemical reactions necessary for adequate film development, again resulting in lower film density. A slow intensifying screen speed would not affect the radiograph density directly, but rather the efficiency of the x-ray exposure transfer to the film, which could also affect image quality negatively, though not directly causing increased density.

Therefore, when considering the relationship between the focal-film distance and film density, a shorter distance indeed results in increased film density.