2011

Table Of Contents
The log space in Composite is very similar to that used by Cineon encoding,
but it does not clamp high dynamic range values, and it is scaled with respect
to the Cineon codes. That is, a Cineon code of 1023 corresponds to a value
of 1.0.
The transformations can be controlled with the negative film gamma, the
Cineon reference, and the linear reference. These reference points are expressed
in units of the log space described above. You can display their value either
as raw or as Cineon codes.
Modifying Negative Film Gamma, Cineon Reference,
or Linear Reference Levels
The transformation between log and linear color spaces is controlled by three
parameters: negative film gamma, Cineon reference, and linear reference.
Gamma controls the contrast, while Cineon reference and linear reference
establish a correspondence between points in the two color spaces. The Cineon
code, specified as the Cineon reference, is transformed to the value specified
as the linear reference. For example, you may want to base the transformation
on the 90% white card and specify a Cineon reference code of 685 and a
corresponding linear reference value of 90.
NOTE All Delog and Log parameters are animatable see Setting Keys Manually
on page 676 and Validating and Applying the Expression String on page 729.
The white reference is mapped to 0.9 in linear space. Cineon codes above
reference white are mapped to values above 0.9, however, these values can
be greater than 1. This tool does not clamp to 1, so there is no loss of
information.
All incoming pixels with values between 1 and 95 produce black pixels.
NOTE All channels are linked by default.
To uniformly modify values with the Log or Delog tool:
Do one of the following:
Drag the red (R), green (G), or blue (B) channel fields to the right to
increase, or to the left to decrease, values uniformly on all three
channels. Alternatively, you can also drag the luminance (L) field to
achieve the same result.
628 | Chapter 26 Color Correction