Knowing the basics of film photography is a step towards understanding how the technical side of filmmaking works.
In fact, even those preferring to go digital all the way can benefit much with the knowledge of film photography.
Whether using 35mm, 16mm, or 8mm film cameras or high-definition (HD) cameras, the very concept of producing moving images is actually the same. Even the use of film speed, which originated from film photography and cinematography, is also used in digital cameras as part of their settings.
Film vs. Digital
Whether using a film camera or digital camera for photography, it follows the same set-up for image production. The primary difference of the two is the actual medium where the image gets processed: a film negative for a film camera; and a sensor for a digital camera. In film photography, the image gets stored through the exposure of the negative to the light that passes through the lens. In digital photography, the image gets stored as a digital file in the camera’s file storage device through the processing of the light through the lens, then going to the camera’s sensor.
In photography and filmmaking jargon, the film speed is often addressed as the ISO (International Service Organization) or ASA (American Standards Association) number. While the current standards utilizes the ISO, filmmakers using the term ASA is still widely used and accepted in a typical film work setting.
Photographic film is available in a wide variety of ASA or ISO speeds such as 25, 100, 400, 800, 1200, and 3200. This film speed measures the sensitivity of the film to light. The lower the ASA number, the less sensitive it is to light. Interestingly, the ASA is also used even in the digital realm. It follows the same idea as how film photography utilizes it. Instead of using an actual film negative, the electronic settings of any professional digital still camera provides options to change from one film speed to another. The same thing goes with motion picture cameras in film and digital formats.
Depending on the type of scene intended to be shot, the ASA number becomes a crucial choice for the filmmaker. Motion picture film is available in a wide variety of ASA speeds such as 50, 100, 200, 320, and 500. If shooting during day time in an exterior location, a motion picture film with lower ASA number or a digital cinema camera setting with a lower ASA number is ideally used. Such film or camera setting requires less light sensitity to properly expose shots. If shooting during night time in a relatively dark room or an exterior location with no strong light source, a motion picture film with higher ASA number or a digital camera setting with a lower ASA number is ideally used. Such film or camera setting requires better light sensitivity to properly expose shots.
On a creative level, when shooting the scene using a specific ASA number, then shooting another version of the same scene using another ASA number, you will get significant differences in exposure and overall look for each scene. The decision on which film speed to use really depends on the overall look and needs of the scene to shoot, as how the director and cinematographer envisions it.