sentence: Photographic film is coated with chemicals that react when light shines on it.
sentences_before: The picture the lens makes is recorded on photographic film. Film is placed inside the camera box. Light coming through the lens, aperture and open shutter shines on the film.
sentences_after: Letting light shine on the film is called 'exposing' the film.
concept_name: photographic film
headings: Photography Film