What does Focal Film Distance (FFD) refer to?

Focal Film Distance (FFD) specifically refers to the distance between the x-ray tube and the film. This distance is crucial because it affects the intensity and quality of the x-ray images produced. A greater FFD can lead to improved image sharpness and reduced distortion, as the x-ray beam diverges more the further it travels from the source. This relationship is a fundamental principle in radiography, influencing exposure and the overall efficacy of the imaging process. FFD must be carefully considered when setting up for an x-ray to ensure optimal results.