Grass Valley Kayak HD v.6.9.3 - Manual (Page 105)

Kayak — User Manual 105
DD Mode Keyer Subpanel
Note The Add Lin and Lum Lin buttons allow selecting three different operational
modes (see below).
The buttons are lit as follows:
Add Key
The Add Key button serves to select the additive key mode. In this mode, an
external unit (e.g. modern caption generators, paint systems) generates and
supplies the key signal and the associated fill signal.
The background signal is multiplied with the key control signal and added
to the supplied fill signal. This mode ensures that the supplied fill signal is
not influenced and that all details contained in it are reproduced true to the
original.
Note Please note that the supplied fill signal must be on top of a black background.
Otherwise, the addition of the signals will yield a discolored background
signal.
Lum Key
The Lum Key button selects the luminance key mode. The key control signal
is derived from the luminance component of the key source signal. The key
control signal controls the transition between background and foreground
(=fill) signal.
Lin Key
Pressing the two buttons Add / Lin and Lum / Lin sets the luminance key to a
linear mode. The key control signal corresponds to the non-amplified and
unlimited luminance signal.
Preset Pattern Key
The Preset Pattern button selects Preset Pattern, which cuts the hole in the
background using an internal wipe pattern generator (or Utility Bus video),
rather than a source’s key cut signal.
Table 2. Table: Key Functions
Key Function Add / Lin (Lin Key) Lum / Lin (Lum Key)
Additive key YES NO
Multiplicative key
Gain = Unity
YES YES
Multiplicative key
Gain < > Unity
NO YES