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Keyer LOG

ToolSets / Keyer

Keyer

2026-09-07

ToolSets/keyer/keyerLOG.nk

keyer

luminance

log

logc

alpha

utility

matte

View on GitHub

Luminance keyer that converts to AlexaV3LogC, keys, then copies the resulting alpha back onto the original input.

Keyer LOG wraps Nuke’s Keyer in an AlexaV3LogC round trip. The plate is converted to LogC, a luminance key is pulled there, then the image is converted back and the alpha is copied onto the untouched original input.

Use it when a straight luminance key on linear or display-referred footage feels harsh or unstable. Working the key in LogC often gives smoother falloff and more controllable range on log-origin plates.

Exposed controls are the standard Keyer knobs: input, output, combine, invert, operation, and range. Default operation is luminance key. RGB and other channels pass through from the source; only alpha is replaced.

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