Download - Options AS

The following table should help to explain the difference between these four modes of
operation.
Overlay mode Description
Effect of fade
PC Out
Outputs only the computer image. Video input is Fades computer
ignored.
image to black level.
Genlock
Outputs only the computer image. All sync,
Fades computer
subcarrier and video levels are generated by the
image to black level.
scan converter, but locked to the video input.
This allows use in situations where a TV or video
monitor should be 'in-sync' with other equipment.
Overlay
Overlays computer image on top of video input,
based on Key Level and Keyer setting. Sync and
subcarrier signals are direct from the video input
(i.e. unit does not re-generate them).
Fades computer
overlay image out, to
reveal video input
behind it.
Mix
Overlays whole computer image (even black
areas) on top of video input. Sync and subcarrier
signals are direct from the video input (i.e. unit
does not re-generate them).
Fades completely
between computer
image and video
input.
Overlay mode function
This is the most complex to understand, but in general:
The color content of a computer graphic pixel is ignored - the luminance is of sole
importance. White is the brightest (highest luminance), followed by yellow, cyan,
green, magenta, red, blue (and black).
Colors much brighter in luminance that the Key Level are overlaid - i.e. they
replace the video background.
Colors slightly above the Key Level are slightly transparent.
Both versions
Colors at the Key Level are blended approximately 50% with the video
background.
Colors slightly below the Key Level are more transparent.
Colors well below the Key Level are not displayed at all.
The level at which colors become opaque or transparent is set by the Keyer value
(V.Soft / Soft / Normal / Hard).
With a Hard Keyer setting, color luminances do not have to be much higher or
lower than the Key Level to become fully overlaid or not displayed at all.
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