Crystal Vision
Control Descriptions
Foreground
Suppression
Adjust this control to set the suppressed backdrop area
to black. Monitor the keyed FG signal and set the
control to the minimum level necessary to give a solid
black in the chroma key backdrop area. This control is
best adjusted after the hue and acceptance controls
have been set and – because because of their
interactive nature – the min and max clip controls set to
their default values. Note that when the suppressed FG
signal and keyed Background signal are added together
to form a final composite, any luminance in the FG
backdrop area will be added to the new background.
This can sometimes be compensated for with BG lift
reduction in the BG Match sub menu of the Colour
Adjust tab, but every attempt should be made to
achieve as close to black as possible. Over-
suppressing will distort edges possibly causing a black
halo around FG objects.
Acceptance
Adjust this control to change the range of colours
about the hue colour (acceptance window) suppressed
by the Foreground suppression circuitry. Monitor the
Keyed FG signal and adjust this control to entirely
suppress the chroma key backdrop colour. If the
acceptance angle is set too small, then due to
variations in backdrop colour, a colour tint may remain
in places. If the angle is set too large then unwanted
suppression may occur on foreground objects. Adjust
the hue control as well to get the best compromise if
there are large variations in backdrop colour. This
control is best adjusted with the suppression control
set mid-way to see the effect most clearly.
Edges and Key Remove
Adjust chroma key settings to remove unwanted keying in black, grey or white
areas. Adjust key levels to remove or enhance shadows. Alter key shape to improve
effect.
Safire 3 User Manual R1.3
33
24 March 2017