The term 'film frame' can be broken down into two crossword solutions: CEL (3 letters) and EXPOSURE (8 letters). CEL is an abbreviation for celluloid, which is a type of transparent plastic film that was used to create animation cels in traditional animation. EXPOSURE refers to the amount of light that is allowed to reach the film when taking a photograph. In photography, the film frame is the area of the film that is exposed to light, resulting in an image.