Apple Cinema Tools 3 - Manual (Page 203)

Appendix A Background Basics 203
Film Edge Code
To aid in locating specific film frames, film manufacturers place numbers along the
edge of the film. These key numbers (also known as latent edge code) appear once the
film is developed. For workprints, film labs can add numbers called ink numbers (also
known as Acmade numbers).
Edge code is essential to your Cinema Tools database because it makes it possible for
you to export cut lists or change lists that specify exactly where your negatives or
workprints need to be cut in order to match your digital edits.
Key Numbers
Key numbers provide both an identification number for each roll of film and an
incremental footage count number used to identify specific film frames. They often
appear as both regular text and as a bar code.
Each film standard uses key numbers differently:
 16mm film can have a key number every 20 frames (most common) or 40 frames,
depending on the film stock. Cinema Tools supports the 16mm-20 format.
 35mm film has a key number every 64 perforations (which works out to every
16 frames with the 4-perf format).
Unlike video timecode, which provides a unique number for each video frame, key
numbers do not appear on every frame of film. For this reason, when identifying a
specific frame in a log book or in Cinema Tools, key numbers have a frame count
extension added specifying the actual frame. A “+08” at the end of a key number
indicates it is the eighth frame from that key number’s first frame.
Key number
UP01101.Book Page 203 Thursday, March 10, 2005 3:16 PM