Tektronix 2200 Manual Do Utilizador

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Super Black is a video signal that is lower than the usual black 
level (7.5 IRE in NTSC; 0 IRE in PAL and Component video). The 
actual level of the signal below black varies from situation to 
situation and is often limited by the device that is used to record 
the signal. Typically 0 IRE is used, although values as low as -5 IRE 
or -10 IRE are being used.

The main reason for using super black is to enable the video, 
including regular black, to be separated by a keyer’s clip and gain 
circuit from the surrounding super black level. This enables a 
recorded video signal which includes black to be keyed into a 
scene without using a separate key signal.

If the video is recorded over super black due to the inability to 
have the key at the same time for later keying, the video should be 
recorded as shaped, as there will be no shaping signal (key) 
available to modify the edges. Key softness, key opacity, and any 
transparent drop shadows will be lost. This signal can only be 
separated from the super black level using a luminance keyer with 
the key clip level set to separate the video fill (including black) 
from the super black level. Super Black there requires all of the key 
edges to be hard.

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