Graphics Reference
In-Depth Information
3
Click on the eyedropper
next to
Screen Colour
,
then sample any green area
in the Comp Window.
Immediately a fine Key is created.
But due to the highly compressed
nature of the footage, the JPEG
codec causes mosquito noise and
color artifacting around the hand's
edges. By adjusting a few
settings, a more than acceptable
Key can be obtained. Detailed
tutorials on the implementation of
Keylight are included with After Effects, so for now we'll focus on fundamental
settings to clean up the image.
4
Set Clip Black to 20.0, Screen Grow/Shrink to
1.5, and Screen Despot
Black to 2.0.
The
Screen Matte
options provide the primary tools for cleaning up your Key.
The options used for this shot included:
Clip Black
- enhances the depth
of the Key, but can remove
some of the foreground
reflections (in scenes with glass
in front of the green/blue screen)
or details in the color you might
need to keep.
Screen Grow/Shrink
- expands
or contracts the generated
Mask's influence; too much of
this setting can remove the fine
detail of hair.
Screen Despot Black
- removes
subtle dark speckles that
contaminate your Key.
