Matte key
Last updated
Matte key is a Utility effect.
What it does
Section titled “What it does”Lumit’s keyer. It changes a pixel’s transparency where a pixel matches a chosen screen colour, so a subject shot against green or blue can be composited over something else.
Parameters
Section titled “Parameters”| Parameter | Control | Range | Default | Unit |
|---|---|---|---|---|
| View | Dropdown | Final result · Screen matte · Status | Final result | - |
| Screen colour | Colour | Each channel 0 to 4, scene-linear | 0, 0.6, 0, 1 | - |
| Screen gain | Slider | 0 to 200; higher | 100 | Per cent |
| Screen balance | Slider | 0 to 100 | 50 | Per cent |
| Despill bias | Colour | Each channel 0 to 4, scene-linear | 0.5, 0.5, 0.5, 1 | - |
| Alpha bias | Colour | Each channel 0 to 4, scene-linear | 0.5, 0.5, 0.5, 1 | - |
| Despill amount | Slider | 0 to 100 | 100 | Per cent |
| Screen pre-blur | Slider | 0 to 20; up to 100 | 0 | Pixels at composition size |
| Clip black | Slider | 0 to 100 | 0 | Per cent |
| Clip white | Slider | 0 to 100 | 100 | Per cent |
| Clip rollback | Slider | 0 to 100 | 0 | Per cent |
| Screen shrink/grow | Slider | -10 to 10; down to -50 and up to 50 | 0 | Pixels at composition size |
| Screen softness | Slider | 0 to 20; up to 100 | 0 | Pixels at composition size |
| Despot black | Slider | 0 to 100 | 0 | Per cent |
| Despot white | Slider | 0 to 100 | 0 | Per cent |
| Inside mask | Masks | This layer’s masks | None | - |
| Outside mask | Masks | This layer’s masks | None | - |
| Replace method | Dropdown | Source · Hard colour · Soft colour · None | Soft colour | - |
| Replace colour | Colour | Each channel 0 to 4, scene-linear | 0.5, 0.5, 0.5, 1 | - |
| Mix | Slider | 0 to 100 | 100 | Per cent |
| Blend | Dropdown | Normal · Darken · Multiply · Colour burn · Linear burn · Darker colour · Add · Lighten · Screen · Colour dodge · Lighter colour · Overlay · Soft light · Hard light · Linear light · Vivid light · Pin light · Hard mix · Difference · Exclusion · Subtract · Divide · Hue · Saturation · Colour · Luminosity | Normal | - |
In the Effect Controls panel:
- Screen matte groups Screen pre-blur, Clip black, Clip white, Clip rollback, Screen shrink/grow, Screen softness, Despot black, Despot white, Inside mask, Outside mask, Replace method, Replace colour, and starts closed.
What each control does
Section titled “What each control does”- View: what the Viewer shows. Final result is the keyed picture.
- Screen colour: the colour being removed.
- Screen gain: how aggressively the matte falls off.
- Screen balance: how the two non-screen channels are weighted against each other when judging a pixel.
- Despill bias: shifts the colour the despill pulls the screen channel down to.
- Alpha bias: shifts what is neutral when judging the matte itself.
- Despill amount: how much screen colour is drained out of the subject.
- Mix: how much of the result replaces the original.
- Matte and Invert drive the strength of the effect from another layer’s brightness; see Effects.
The Screen matte group cleans up what the key leaves:
- Clip black: the matte level at or below which a pixel becomes fully transparent.
- Clip white: the level at or above which a pixel becomes fully opaque.
- Clip rollback: eases both clips back toward the unclipped matte.
- Replace method: what colour is put where spill was removed.
- Replace colour: the colour those two methods blend in.