FOCUS Enhancements Bridge/Router MX-4DV - Manual (Page 100)

MX-4 DV U SER G UIDE C HAPTER 10 96
• The color used for the background must not appear elsewhere in the image. For example, if
Kong’s head (in the example above) contains colors close to the chromakey background, the
picture of the bridge would appear in those areas. (Professionals often use a special “blue
screen” paint for the backdrop when filming the image.)
• The color of the background must be evenly distributed. Glare from camera lights and shad-
ows of the subject can alter the background color. MX-4 DV’s chromakey circuitry might not
be able to handle the different values, thereby spoiling the illusion.
This chapter explains how to prepare footage for use with the chromakey feature. Of course, screen
images appear in grayscale in this book.
The Background footage shows traffic moving along a freeway or highway.
The Keyed footage, specially prepared, shows our intrepid hero flying against a solid colored
background.
The Chromakey footage is the result of combining the background footage and keyed footage
using the MX-4 DV chromakey feature.
P
REPARING THE
B
ACKGROUND
F
OOTAGE
Preparation of the background footage does not require anything special. It might be footage of
automobile traffic taken from a bridge.
TIP
The more unusual or dramatic the Background footage the greater the final effect of the chromakey.
Background
Footage
Keyed
Footage
Chromakey
Footage