Apple Color 1.5 - Manual (Page 315)

As the processed image makes its way from the Primary In to the Secondaries to the Color
FX rooms, the corrections in each room are applied to the image that’s handed off from
the previous room. Since the Primary Out room is the very last correction room in every
grade, it processes the image that’s output from the Color FX room. You can take
advantage of this to apply overall corrections to the post-processed image.
In the following example, a series of corrections that affect saturation are made in each
of the rooms, but the Primary Out room is used to reduce the saturation of the end result.
You can see that the final correction modifies the collective output from every other
room.
Primary Out Adjustment
(Saturation adjustment affects the sum
of all corrections)
Secondary Adjustment
(Boost orange saturation) Primary In Adjustment
(Original image adjustment)
Color FX Adjustment
(Add blue vignette)
Ceiling Controls
Lastly, the Primary Out room has a single group of controls that aren’t found in the Primary
In room. The Enable Clipping button in the Basic tab of the Primary Out room lets you
turn on the effect of the three individual ceiling parameters for the red, green, and blue
color channels of the current shot.
This option lets you prevent illegal broadcast values in shots to which you’re applying
extreme Primary In, Secondary, or Color FX corrections if you don’t want to turn on
Broadcast Safe for the entire program.
The Ceiling parameters can also be used to perform RGB limiting for hard-to-legalize clips.
315 Chapter 12 The Primary Out Room