Grass Valley Kayenne K-Frame v.7.0 - Manual (Page 88)

88 KAYENNE K-FRAME — User Manual
Section 4 — Video Mix/Effects
The smaller the difference between Clip Hi and Clip Lo , the higher the keyer
gain. High gain amplifies noise present in the transition between trans-
parent and opaque. The correct setting is with
Clip Hi and Clip Lo set to just
barely achieve opacity and transparency, respectively.
1. Touch the stage 2 Key Controls data pad to activate these controls. You can
now manually adjust keyer clipping controls.
2. Select Show Key in the Keyer menu ( Figure 45 ) and look at the ME
preview output on a picture and waveform monitor.
Figure 45. Key Controls
3. Adjust Clip Hi so that all areas of the foreground objects are white. If
Clip Hi is set too low (too far clockwise), much of the translucent areas
will be forced to be fully opaque, hardening the key and darkening the
transition area between background and foreground.
4. Clip Low can be set accurately with Auto Setup. Adjust Clip Low so that all
areas of the backing color are black. If Clip Lo is set too high (too far
counter-clockwise), translucent areas will be forced fully translucent,
hardening the key.
Note When adjusting clip levels, remember that areas on the edge of the fore-
ground subject should show as shades of gray. Gray indicates areas of trans-
lucency, which is desirable in chroma keying.