Which feature enhances the effectiveness of fast films?

The feature that enhances the effectiveness of fast films is greater radiosensitivity. Fast films are designed to respond more readily to radiation compared to slower films, allowing them to produce an adequate image with less exposure to radiation. This increased radiosensitivity means that the film can capture the required detail and contrast more efficiently, resulting in a clearer image while reducing the overall radiation dose required during imaging procedures.

While options related to exposure time, thickness, and temperature stability have their own relevance in the context of film quality and performance, they do not directly contribute to making fast films more effective in the same way that increased radiosensitivity does. This characteristic is essential in various situations such as medical imaging, where reducing exposure time is crucial for patient safety while still maintaining image clarity.