Apple Motion 5.1.1 - Manual (Page 498)

Chapter 13 Keying 498
The background layer shows through as long as the View control in the Filters Inspector is set
to Composite.
Note: If the clip you add a Keyer filter to is not visible in the Canvas, the initial key is pulled based
on the first or last frame in which the subject appears, whichever is closest to the playhead.
4 If the automatic key is too aggressive (keying out soft details of the keyed subject that you want
to preserve), slowly drag the Strength slider left to reduce the tolerance (core transparency) of
the matte until you’re satisfied with the amount of edge detail in the key.
Doing so allows areas of marginal transparency like hair, smoke, and reflections to show through.
In general, it’s better to err on the side of a less aggressive key, using the parameters within the
Matte Tools group to fine-tune the soft details you’re trying to preserve.
Strength set to 100% Strength set to 35%
Tip: If you open the Color Selection controls while adjusting the Strength slider, you can see how
the Chroma and Luma parameters are affected.
Override automatic color sampling and set your own key colors
1 Select the applied Keyer filter in the Layers list, then open the Filters Inspector or HUD.
2 Set the Strength slider to 0.
Automatic color sampling is disabled, and the green screen background becomes visible in
the Canvas.
67% resize factor