A 35mm film projector is a device that continuously moves film along a path so that each frame of the film is stopped for a fraction of a second in front of a light source. The light source provides extremely bright illumination that casts the image on the film through a lens onto a screen.
Film vs. digital: the most contentious debate in the film world, explained
The transformation of the multiplex coincided with the transformation of the way films were shot. For years, cinematographers — the camera specialists who oversee a movie’s photography — had expressed skepticism about the ability of digital cameras to compete with film. Compared with 35mm, early digital cameras weren’t light- or color-sensitive enough, and didn’t provide the same level of resolution.