What causes a film to be elongated in radiography?

Elongation of a film in radiography is primarily caused by insufficient vertical angulation during the imaging process. When the vertical angulation is too low, the X-ray beam does not project the anatomical structures accurately onto the film, which can result in the appearance of stretched or elongated images. This can particularly occur in certain views, such as when taking periapical radiographs, where proper angling is crucial to capture the correct dimensions of the tooth and surrounding bone.

In contrast, excessive vertical angulation typically results in a foreshortened image, not elongation. Overexposure would lead to an overly dark image but would not specifically cause elongation. Using an incorrect film type may affect image quality and detail but does not inherently alter the dimensional aspect of the image, such as elongation.