determine exposure, the camera alone imposes three variables: aperture, shutter speed, and film ISO. The environment, controllable or not, will dictate other variables. Lighting is never easy. Every time you strike a light, you cast a shadow somewhere else. Cinematographers, the head of camera and lighting, have the largest crew on any film set. His right arm, the gaffer (chief electrician), manages the light and grip crew. They are responsible for setting up lights, black wrapping windows, mounting stands, pushing or pulling dollies, holding b-boards, etc. Setting up light is what drains most of the time in any film production. Directors of photography are inventive problem solvers. They must be very attentive of the environment where they’re shooting because apparently useless objects can actually come quite handy. ]