A unique number for every frame of film.

Negative Matching

Keykodes

Printed into the edge of negative film is a series of running numbers: in 35 mm they appear every foot (16 frames), in 16 mm they are every six inches (20 frames). As the numbers increase by one each time, they can be used to uniquely identify any frame within the production. The numbers also include an alpha prefix, which identifies the type of emulsion, and a roll number. Alongside every edge number is a corresponding machine-readable barcode. These edge numbers (or Keykode) are exposed into the negative raw stock during manufacture: they do not become visible until the negative is processed.

A Keykode reader can read the barcode as the film is passed through a bench rewinder. ...

Get Film Technology in Post Production, 2nd Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.