Separation masters are a method of long-term preservation for most modern

color motion picture film Color motion picture film refers both to unexposed color photographic film in a format suitable for use in a motion picture camera, and to finished motion picture film, ready for use in a projector, which bears images in color. The first colo ...

. Since monopack color film - (where materials for registering all the colors of the spectrum are contained on one film - its opposite is

bipack colour In bipack color photography for motion pictures, two strips of black-and-white 35 mm film, running through the camera emulsion to emulsion, are used to record two regions of the color spectrum, for the purpose of ultimately printing the images, ...

film where two films face each other and the lower spectrum reds and yellows are on one film and the higher spectrum greens and blues are on another film - see

Technicolor Technicolor is a series of Color motion picture film, color motion picture processes, the first version dating back to 1916, and followed by improved versions over several decades. Definitive Technicolor movies using three black and white films ...

three strip) used in such processes as ECN, ECP and their successive revisions - contains photographically active

color couplers Dye coupler is present in chromogenic film and paper used in photography, primarily color photography. When a color developer reduces ionized (exposed) silver halide crystals, the developer is oxidized, and the oxidized molecules react with dye ...

which remain in the film after development, the emulsion will continue to produce chemical reactions in the image which cumulatively create a color fading, usually heavily biased towards the pink spectrum. In order to protect against this occurrence, the technique of separation masters was created. Separation mastering is essentially an inversion of the

three-strip system, which used filtration to create three

black and white Black-and-white (B&W or B/W) images combine black and white in a continuous spectrum, producing a range of shades of grey. Media The history of various visual media began with black and white, and as technology improved, altered to color. ...

masters each sensitized for one of the

RGB The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three addi ...

spectrums and then printed the negatives with a

CMYK The CMYK color model (also known as process color, or four color) is a subtractive color model, based on the CMY color model, used in color printing, and is also used to describe the printing process itself. The abbreviation ''CMYK'' refers ...

colorspace. In separation mastering, the

original camera negative The original camera negative (OCN) is the film in a traditional film-based movie camera which captures the original image. This is the film from which all other copies will be made. It is known as raw stock prior to exposure. The size of a roll v ...

is used to create three black and white copies, each one filtered for one of the RGB spectrums. The black and white process is considered inert after development and thus should be more stable for long-term archival, preservation, and restoration (although the

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 majorit ...

may eventually decay regardless).

References

Film and video technology {{filmmaking-stub