One-light

In audio post-production, a one-light refers to a videotape work cassette or digitized video file made during a specific type of film-to-video telecine transfer. Generally sourced from a pre-print element, (such as an interpositive or internegative), this transfer creates a frame-for-frame representation of each film reel in its entirety, including all head and tail leader. It should include two window burn-ins: one with the video time code and the other with a foot + frames counter.

Using a one-light as picture reference, an engineer can sync audio to the time code of the video and perform all of his or her work in the digital realm. Once completed, the audio can be converted back to film speed and used to create mags or optical soundtrack negatives that will sync perfectly with the film picture element.

Although the term one-light has come to refer to the videocassette or digitized video file that results from the telecine transfer, the name derives from the process itself. To save time and money, a one-light transfer is created using a single exposure, (or one-light), without concern for color and lighting balance. While this sacrifices some image quality as individual scenes have not been color-corrected, it enables the telecine operator to complete the transfer as quickly and inexpensively as possible.