Sony DVS-7300 System User Manual page 32

2 Key fill and key source selection
buttons
MATTE FILL: Pressing this button,
turning it on, selects a color matte
produced by the switcher as the key
fill signal.
When this button is off, the signal
selected on the key fill bus is used as
the key fill. When all three of this
button, the AUTO SEL button and the
SPLIT button are off, the signal
selected on the key fill bus is also used
as the key source (self-keying).
AUTO SEL (auto selection): Press this
button, turning it on, to use the signal
assigned in a setup menu to the current
key fill as the key source.
SPLIT: Press this button, turning it on, to
use the signal on the key source bus as
the key source. To select the signal on
the key source bus, hold down this
button, and press a cross-point button
in the auxiliary bus bank or in the M/E
bank a cross-point button in the K row
(BKDS-7011/7023) or K1 or K2 row
(BKDS-7012/7021/7022).
To use the signal selected on the key
fill bus as the key source, press both
the SPLIT button and the AUTO SEL
button simultaneously, so that both are
off.
3 Key type selection buttons
LUM (luminance): A hole is cut at a
certain level of the Y (luminance)
signal of the key source, and the key
fill signal inserted.
• In a D2 system, the key source is
passed through a filter, and the
resulting Y signal is used to
determine the key.
• In a D1 system, the key source Y
signal is passed through a filter to
apply S-curve compensation, and the
resulting signal is used to determine
the key.
LIN (linear): A hole is cut in the
background and the key fill signal
inserted. Compared with a luminance
key, there is a reduced variability in
gain.
• In a D2 system, the key source signal
including the chrominance
component is used to determine the
key.
• In a D1 system, the key source Y
signal is used to determine the key.
CLEAN: In a luminance or linear key the
key source is used as a mask on both
the background (i.e. to cut the hole)
and on the key fill (i.e. trimming it to
fill the hole). The clean key
technique, on the other hand, does not
mask the key fill, but simply mixes it
with the background from which the
hole has been cut. This means that the
key fill signal must already be
trimmed to fit the hole (i.e. black
everywhere else).
Chapter 2 Location and Function of Parts
2-17