Apple Shake 4 - Manual (Page 642)

642 Chapter 23 Color Correction
aLo
A low color control for the alpha channel.
High Color
Pixels greater than or equal to Hi value go to 1. At 8 or 16 bits per channel, pixels
greater than this value are clamped at 1.
aHi
A high color control for the alpha channel.
Fade
The Fade node multiplies the RGBA channels. It differs from Brightness in that Fade also
affects the alpha channel. For individual channel control, use Mult.
A neat trick is to fade to 0. This effectively deactivates all nodes above the Fade node in
the tree.
Note: Premultiplication is not a concern with the Fade node, since Fade treats the RGBA
channels evenly.
Parameters
This node displays the following control in the Parameters tab:
Value
The brightness factor. Greater than 1 increases brightness; less than 1 darkens it. A
value of 0 is complete black.
Gamma
The Gamma node applies a gamma to your image. A value of 1 equals no change.
Shake’s ability to use expressions can be particularly useful here; for example, to invert
the gamma of 1.7, type “1/1.7” as your gamma value. Typing “.588” isn’t nearly as slick.
Parameters
This node displays the following controls in the Parameters tab: