Optics
Halation
A halo around highlights: red travels furthest, so the colour follows.
Controls
- threshold
- What counts as light. It moves the edge of the halo, not its strength — white glows fully at any threshold
- radius
- How far the red goes, and red goes furthest of the three
- separation
- How far behind the other two channels lag. At zero the halo is neutral, which is just a bloom; higher, it reddens
- intensity
- A number from 0 to 2, 0.7 by default.
- quality
- How many blur passes are stacked. One leaves a hard step at the edge of the halo, three a soft falloff
- contrast
- A number from -1 to 1, 0 by default.