I got this from a book on technicolor.
At a third remove from the ideal print are reproductions of Technicolor films
using photochemical processes like Eastmancolor. These versions present a distinct
set of problems because the processes rely on different means for producing
color.Where Technicolors dye-transfer printing mechanically dyed the image on
the release stock, processes like Eastmancolor depend on coupler development,
that is, the formation of dye by the interaction of chemicals within various layers
of the emulsion. These multilayer films are far more complex, both physically and
chemically, than the materials used by Technicolor.5 Since the great majority of
color films available today are Eastmancolor versions, we must be aware of the
differences between them and a Technicolor original.
Dr. Richard Goldberg, vice president of research and development for Technicolor
during the 1950s, oversaw the reformulation of the dye-transfer process for
use with Eastmancolor stock, and he has expert knowledge of the differences between
the processes. Goldberg explained to me that one strength of dye-transfer
was color separation, or the ability to precisely control individual color components.
Release prints would be dyed three times with a different matrix, a sort
of rubber stamp, carrying yellow, cyan, and magenta dye. Each matrix could be
independently controlled to alter tone scale and color rendition, and the density
of each dye could be modified to control color contrast. Further, the matrices
used to produce prints were made from the original negative. The processing of
Eastmancolor stocks, on the other hand, involves the creation of internegatives
and interpositives, steps between the original negative and the final print, leading
to interimage contamination, or cross-talk, between the various layers of
color. As an example, Goldberg noted that Eastmancolor printing has difficulty
withholding cyan information from flesh tones, which should be very rich in magenta
and yellow.6 For similar reasons, yellows in Eastmancolor tend more toward
orange than in Technicolor.7 Most significantly, the complexity of the chemical
reactions in Eastmancolor film is responsible for the well-known problem of color
fading, in which the image loses its blue information and takes on a pinkish or
salmon tint. Color in aTechnicolor print has much greater stability, partly because
Technicolor prints are comparatively simple.8
At a third remove from the ideal print are reproductions of Technicolor films
using photochemical processes like Eastmancolor. These versions present a distinct
set of problems because the processes rely on different means for producing
color.Where Technicolors dye-transfer printing mechanically dyed the image on
the release stock, processes like Eastmancolor depend on coupler development,
that is, the formation of dye by the interaction of chemicals within various layers
of the emulsion. These multilayer films are far more complex, both physically and
chemically, than the materials used by Technicolor.5 Since the great majority of
color films available today are Eastmancolor versions, we must be aware of the
differences between them and a Technicolor original.
Dr. Richard Goldberg, vice president of research and development for Technicolor
during the 1950s, oversaw the reformulation of the dye-transfer process for
use with Eastmancolor stock, and he has expert knowledge of the differences between
the processes. Goldberg explained to me that one strength of dye-transfer
was color separation, or the ability to precisely control individual color components.
Release prints would be dyed three times with a different matrix, a sort
of rubber stamp, carrying yellow, cyan, and magenta dye. Each matrix could be
independently controlled to alter tone scale and color rendition, and the density
of each dye could be modified to control color contrast. Further, the matrices
used to produce prints were made from the original negative. The processing of
Eastmancolor stocks, on the other hand, involves the creation of internegatives
and interpositives, steps between the original negative and the final print, leading
to interimage contamination, or cross-talk, between the various layers of
color. As an example, Goldberg noted that Eastmancolor printing has difficulty
withholding cyan information from flesh tones, which should be very rich in magenta
and yellow.6 For similar reasons, yellows in Eastmancolor tend more toward
orange than in Technicolor.7 Most significantly, the complexity of the chemical
reactions in Eastmancolor film is responsible for the well-known problem of color
fading, in which the image loses its blue information and takes on a pinkish or
salmon tint. Color in aTechnicolor print has much greater stability, partly because
Technicolor prints are comparatively simple.8
