What happens to image resolution when a faster speed film is substituted for a slower one?

When a faster speed film is used in radiographic testing, the image resolution typically decreases due to the inherent characteristics of the film. Faster speed films are more sensitive to radiation, allowing them to capture images with less exposure time. However, this increased sensitivity comes at the expense of detail resolution.

Faster films contain larger silver halide crystals, which can capture greater amounts of radiation but also contribute to less sharpness in the final image. The larger crystal sizes mean that fine details, which can be critical for identifying defects in the material being tested, might not be captured as clearly. Therefore, while faster films are advantageous for reducing exposure time and improving overall workflow, they often result in a loss of image resolution compared to slower speed films, which provide more detailed images due to their finer grain and improved sharpness.