blanking level

So, while there is no difference between the black and the blanking levels in most systems they differ by 50 mV.

In video technology, blanking level is the level of the composite video signal during the front and back porches of the video signal.

So white corresponds to 100 IRE units and blanking level corresponds to 0 IRE units.

PAL sets the black level the same as the blanking level, whilst NTSC sets the black level approximately 54 mv above the blanking level.

In the PAL television standard, the blanking level corresponds to the black level, whilst other standards, most notably NTSC, set the black level slightly above the blanking level on a 'pedestal'.

The black level and blanking level of the NTSC-J signal are identical (at 0 IRE), as they are in PAL, another video standard, while in American NTSC, black level is slightly higher (7.5 IRE) than blanking level.