5

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.
If necessary, you can fine-tune the default color sampling using the Sample Color and
Edges tools in the Filters Inspector or HUD. Alternatively, you can override the Keyer filter’s
default sampling, then set the key colors manually. The next example describes that
method.
To 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.
651Chapter 13 Keying