Tektronix Grass Valley 3000 - Manual (Page 163)

4-25
Luminance and Linear Keying Operations
5. Clip and gain adjustments are done differently for luminance
and linear keying. In the Luminance Key Mode, clip and gain
have a wider range of control. In Linear Key Mode, clip and
Gain adjustments produce a modified Linear Key. This is
indicated by the LUM KEY button being lit as well as the LIN
KEY. To clear the modification, press LIN KEY again; the LUM
KEY light will go out. With these facts in mind:
Set GAIN fully on (CW) and watch the preview monitor as
you adjust CLIP to create the key. The key edge may look
ragged; reduce GAIN to soften up the edge.
6. If you want to split the key (select a hole-cutting source
different from the one assigned to the selected fill crosspoint)
you can do the following:
Select the fill video from the key bus, hold down the VIDEO
KEY (or the AUTO SELECT KEY ) button, and select a Key bus
source crosspoint to be used as the hole-cutter.
7. The split source crosspoint lights when you select it, and
lights anytime you hold down
VIDEO KEY or AUTO SELECT
KEY .
8. To turn off a split key, hold down the VIDEO KEY or AUTO
SELECT KEY button, and reselect the Key bus fill video
crosspoint .
NOTE: A single key can be split two different ways using VIDEO KEY
and AUTO SELECT KEY . Its appearance will change depending on
which key split modifier is selected.