Grass Valley Kayenne K-Frame v.7.0 - Manual (Page 87)

KAYENNE K-FRAME — User Manual 87
Setting Up a Chroma Key
6. Press the Auto Setup button in the Multi-Function area. Preview for that
ME will now display the chroma key source with a superimposed
cursor. The cursor actually represents a box of 16 x 16 pixels.
7. Use the joystick to position the cursor on the backing color. Select a
darker area, if one exists, to optimize the backing color suppression.
8. Press the button on top of the joystick. The chroma key will be set up
automatically using the average of the colors selected by the cursor box.
Because
Reshape was off, fine edges of the key will be preserved.
9. If this chroma key is acceptable, you are done. If set, lighting, or other
conditions prevent the result from being acceptable, you need to decide
whether to adjust the chroma key manually or use Auto Setup with
Reshape.
• Manual adjustment permits retention of fine edge detail (see the
Switcher Concepts Manual for more information). In particular, if
there are problems with translucent areas (hair, smoke) secondary
suppression controls can be useful.
• Auto Setup with Reshape produces a chroma key with harder
edges, but accommodates wider set variations (see below).
Reshaping a Chroma Key Using Auto Setup
If the set is lit unevenly or has other problems, Reshape is available to help
solve the problem. A better alternative, if time permits, is to adjust the
lighting on the set to even out the backing color. This may improve the key
so that Reshape is not needed.
1. If you decide you must use Reshape, follow the Auto Setup procedure
described above, but in
Step 5 touch Reshape on in the Keyer menu to
turn it on (its green indicator will illuminate). After selecting the
backing color area and touching the top button on the joystick, the
chroma key will be set up with coarser values better able to handle set
variations.
2. If this chroma key is acceptable, you are done. If you are still not
satisfied, you can fine tune the chroma key using manual adjustments.
Adjusting Chroma Key Controls
The purpose in adjusting Clip H i and Clip Low is to cause the proper hole to
be cut in the background. All areas of the backing color should be full back-
ground while all areas of the foreground should make the background
completely invisible. The easiest way to do this is to observe the key signal
while making your adjustments.