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Keyer LOG

ToolSets / Keyer

Keyer

2026-09-07

ToolSets/keyer/keyerLOG.nk

keyer

luminance

log

matte

colorspace

alexa

utility

View on GitHub

Runs a luminance key in AlexaV3LogC space and copies the matte onto the original plate.

Keyer LOG converts the input to AlexaV3LogC, runs Nuke’s Keyer there, converts back, and copies the resulting alpha onto the untouched input RGB.

Use it when a luminance pull benefits from log-encoded response—typical on Alexa LogC plates or when linear luminance over-weights highlights and crush in the shadows.

The group exposes the internal Keyer controls: input, output, combine, invert, operation, and range. Color passes through unchanged; only alpha is written.

Script code

set cut_paste_input [stack 0]
version 13.0 v1
push $cut_paste_input
Group {
 name keyerLOG
 tile_color 0x421010ff
 selected true
 xpos -364
 ypos 369
 addUserKnob {20 User l KeyerLOG}
 addUserKnob {41 input T Keyer1.input}
 addUserKnob {41 output T Keyer1.output}
 addUserKnob {41 combine l "" -STARTLINE T Keyer1.combine}
 addUserKnob {41 invert T Keyer1.invert}
 addUserKnob {41 operation T Keyer1.operation}
 addUserKnob {41 range T Keyer1.range}
 addUserKnob {26 "" +STARTLINE}
 addUserKnob {22 btn l DerekVFX.ca T "\1" +STARTLINE}
}
 Input {
  inputs 0
  name Input
  xpos -267
  ypos 178
 }
set N8aa78f00 [stack 0]
 Colorspace {
  colorspace_out AlexaV3LogC
  name Colorspace1
  label "\[value colorspace_in] - \[value colorspace_out]"
  xpos -152
  ypos 204
 }
 Keyer {
  operation "luminance key"
  name Keyer1
  xpos -152
  ypos 242
 }
 Colorspace {
  colorspace_in AlexaV3LogC
  name Colorspace2
  label "\[value colorspace_in] - \[value colorspace_out]"
  xpos -152
  ypos 313
 }
push $N8aa78f00
 Copy {
  inputs 2
  from0 rgba.alpha
  to0 rgba.alpha
  name Copy1
  xpos -267
  ypos 352
 }
 Output {
  name Output1
  xpos -267
  ypos 406
 }
end_group