What physical property does a lead foil enhance when used during radiographic exposure?

When lead foil is used during radiographic exposure, it enhances film density. In radiographic testing, particularly in film radiography, the density of the film is crucial as it indicates the degree of exposure the film has received from radiation. The lead foil acts as a radiation filter; it absorbs excess scattered radiation that does not contribute to the image, helping to improve the contrast and overall quality of the radiographic film. This results in a clearer difference between the areas of the film that have been exposed to radiation and those that have not.

An increase in film density means that the areas of high exposure will appear darker, which is essential for identifying defects in the material being examined. As a result, the use of lead foil effectively optimizes the visibility of any flaws or features within the object under inspection, ultimately aiding in the interpretation of the radiographs.