KeyKode is an Eastman Kodak Company advancement on edge numbers, which are letters, numbers and symbols placed at regular intervals along the edge of 35 mm and 16 mm film to allow for frame-by-frame specific identification. It was introduced in 1990.

KeyKode is a variation of time code

Time code

A timecode is a sequence of numeric codes generated at regular intervals by a timing system.- Video and film timecode :...

 used in the post-production

Post-production

Post-production is part of filmmaking and the video production process. It occurs in the making of motion pictures, television programs, radio programs, advertising, audio recordings, photography, and digital art...

 process which is designed to uniquely identify film frame

Film frame

In filmmaking, video production, animation, and related fields, a film frame or video frame is one of the many still images which compose the complete moving picture...

s in a film stock

Film stock

Film stock is photographic film on which filmmaking of motion pictures are shot and reproduced. The equivalent in television production is video tape.-1889–1899:...

.

Edge numbers

Edge numbers (also called key numbers or footage numbers) are a series of numbers with key lettering printed along the edge of a 35 mm negative at intervals of one foot (16 frames or 64 perforations) and on a 16 mm negative at intervals of six inches (twenty frames). The numbers are placed on the negative at the time of manufacturing by one of two methods:

Latent image exposes the edge of the film while it passes through the perforation machine. This method is primarily utilized for color negative films.

Visible ink is sometimes utilized to imprint on the edge of the film - again in manufacturing - at the time of perforations. The ink, which is not affected by photographic chemicals, is normally printed onto the base surface of the film. The numbers are visible on both the raw stock (unexposed) and processed (exposed and developed) film. This method is primarily utilized for black & white negative film.

The edge numbers serve a number of purposes. Every key frame is numbered with a multi-digit identifier that may be referred to later. In addition, a date of manufacturing is imprinted, then the type of emulsion and the batch number. This information is transferred from the negative (visible once developed) to the positive prints. The print may be edited and handled while the original negative remains safely untouched. When the film editing

Film editing

Film editing is part of the creative post-production process of filmmaking. It involves the selection and combining of shots into sequences, and ultimately creating a finished motion picture. It is an art of storytelling...

 is complete, the edge numbers on the final cut film correspond back to their identical frames on the original negative so that a conform edit can be made of the original negative to match the work print.

Laboratories can also imprint their own edge numbers on the processed film negative or print to identify the film for their own means. This is normally done in yellow ink. A common workflow for film editing involves edge-coding printed film simultaneously with the film's synchronized audio track, on 35mm magnetic film, so that a foot of film and its synchronized audio have identical edge numbers.

KeyKode

With the popularity of telecine transfers and video edits, Kodak invented a machine readable edge number that could be recorded via computer, read by the editing computer and automatically produce a "cut list" from the video edit of the film.

To do this, Kodak utilized the USS-128 barcode

Barcode

A barcode is an optical machine-readable representation of data, which shows data about the object to which it attaches. Originally barcodes represented data by varying the widths and spacings of parallel lines, and may be referred to as linear or 1 dimensional . Later they evolved into rectangles,...

 alongside the human-readable edge numbers. They also improved the quality and readability of the human-readable information to make it easier to identify. The Keykode consists of 12 characters in human-readable form followed by the same information in barcode form. Keykode is a form of metadata identifier for film negatives.

Keykode deciphered

An example Keykode:

KU 22 9611 1802+02.3

• The first two letters in the KeyKode are the manufacturer code (E and K both stand for Kodak, F stands for Fuji
  Fujifilm
  is a multinational photography and imaging company headquartered in Tokyo, Japan.Fujifilm's principal activities are the development, production, sale and servicing of color photographic film, digital cameras, photofinishing equipment, color paper, photofinishing chemicals, medical imaging...
  
  , etc.) and the stock identifier, respectively (in this case Kodak's U standing for 5279 emulsion); each manufacturer has different stocks' naming convention for their emulsion codes.
• The next six numbers in the KeyKode (usually split in 2+4 digits) are the identification number for that roll of film. On Kodak film stocks, it remains consistent for the entire roll. Fuji Stocks will increment this number when the frame number advances past "9999".
• Computers read the (optional) frame offset (marked every four perforations on actual film by a single "-" dash) by adding digits to the KeyKode after the plus sign. In this case, a frame offset of two frames (with respect to the film foot) is specified. The number of frames within a film foot depends on both the film width and the frae pulldown itself, and can also be uneven within the same roll, but rather repeat periodically (like in the 35mm 3perf. pulldown).
• The last (optional), dot-separated number is the perforation offset which, if preceded by a frame offset like in the above example, is a bias within the just-specified frame; otherwise (as interpreted by most DI
  Digital intermediate
  Digital intermediate is a motion picture finishing process which classically involves digitizing a motion picture and manipulating the color and other image characteristics. It often replaces or augments the photochemical timing process and is usually the final creative adjustment to a movie...
  
   software) this considered to be an offset within the whole film foot.

EASTMAN 5279 167 3301 122 KD

• These numbers are consistent for a whole batch of film and may not change in many rolls. EASTMAN is the film manufacturer, 5279 is the stock type identifier. The next three numbers (167) is the emulsion batch number. The next series of four digits (3301) is the roll and part code, followed by the printer identification number that made the Keykode (122) and finally a two letter date designation (KD). In this case, KD=1997.

See also

• 35 mm film
  35 mm film
  35 mm film is the film gauge most commonly used for chemical still photography and motion pictures. The name of the gauge refers to the width of the photographic film, which consists of strips 35 millimeters in width...
  
  
• Color motion picture film
• Filmstock
• List of motion picture film stocks
• Film base
  Film base
  A film base is a transparent substrate which acts as a support medium for the photosensitive emulsion that lies atop it. Despite the numerous layers and coatings associated with the emulsion layer, the base generally accounts for the vast majority of the thickness of any given film stock...
  
  
• Time code
  Time code
  A timecode is a sequence of numeric codes generated at regular intervals by a timing system.- Video and film timecode :...
  
  

External links

• Kodak Keykode home page