Dsk - Down Stream Keying - Cg (Graphic Overlay) - Datavideo SE-900 Instruction Manual

There are only three settings to adjust for Luma Keying.
2. KEY LEVEL MAX - This sets the upper parameter for the key. 255 would remove the entire range up to
pure white, whereas 0 would remove just pure black
3. KEY LEVEL MIN - This sets the lower parameter for the key.
The range between the MAX and MIN determines how many mid tone colours are keyed, the tighter the
range the fewer the colours.
4. TRANSPARENCY - This sets the transparency level of the remaining overlay.
Typical settings for an overlay where you want to remove a white background would be:
Key Level Max = 255
Typical settings for an overlay where you want to remove a black background would be:
Key Level Max = 50

DSK - Down Stream Keying - CG (Graphic Overlay)

The SE-900 has either internal or external downstream keying, this enables CG overlay to be added to the
finished output.
External DSK relies on an external card, such as a Black magic Design Card, to overlay the graphics and
return the signal to the SE-900.
With Internal DSK the SE-900 does the keying internally, removing the background from the CG input. The
levels can be set to remove black levels or white levels according to the graphic you are working with.
Though the Internal DSK is able to produce an acceptable result it will always be possible to achieve better
results using External Keying.
The SDI CG Overlay Board has two output sockets and two input sockets.
There is actually only one output and one input, but for extended cable runs
it is sometimes beneficial to run a pair of SDI cables.
To use Internal DSK simply connect the CG output from your PC or external
Graphic Generator to one of the SDI Overlay In Sockets.
To use External DSK connect one of the SDI Overlay Outputs to the input
on your external keyer, and then connect the output of the external keyer to
one of the SDI Overlay In Sockets.
Key Level Min = 235
Key Level Min = 0
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