Which of the following is NOT a type of radiographic film?

The term "regular film" is not typically used to define a specific type of radiographic film within the context of medical imaging. Radiographic films are categorized based on their specific characteristics and intended applications, such as screen film, which is designed to be used with a screen that converts X-rays into visible light, and high-speed film, which is engineered for sensitivity to radiation, allowing for faster exposures. Daylight film, on the other hand, is made to be processed in ambient light conditions, eliminating the need for a darkroom.

Therefore, selecting "regular film" as an answer indicates a lack of a defined category that aligns with the established types of radiographic films, making it the correct option in this context.