Which film speed requires the least amount of radiation?

The film speed that requires the least amount of radiation is E speed. Film speed, measured in terms of its sensitivity to radiation, indicates how much exposure is needed to produce a quality image. Faster film speeds, like E speed, are more sensitive to radiation, meaning they can achieve the desired image quality with a lower amount of exposure.

In practical terms, using E speed film allows for quicker imaging procedures as it requires less radiation to produce a diagnostic-quality image compared to slower films such as D, C, or B speeds. While slower speed films may produce high-quality images under optimal conditions, they necessitate higher doses of radiation to achieve the same results, making E speed more efficient and safer for patients and healthcare providers.