Blacker Than Black Means Different Things?

Discussion in 'Playback Devices' started by Allan Jayne, Jun 18, 2004.

  1. Allan Jayne

    Allan Jayne Cinematographer

    Nov 1, 1998
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    Does blacker than black need standards let alone adherence to standards?

    Does blacker than black require that the TV and the DVD player be coordinated?

    This question might best be answered by Guy Kuo but perhaps others may be able to shed light on it.

    The ambiguity may be explained by the diagram below. On the DVD black to white is represented by a scale of 0 to 255 (8 bits) where normally 16 is black and 235 is white. (Some disks use 0 to 15 for additional black detail) The IRE scale has 7.5 as black and 100 as white.

    Is enhanced black A and normal black C? If the TV does not pass 0 to 7.5 IRE than this doesn't do any good.

    Or is enhanced black B and normal black D?

    If the TV gave its maximum black at IRE 7.5 then B from a DVD player would give all the shadow details from disks using 0 to 15 as part of the black range, no?

    Or are there permutations that I have not shown?

    Or does it vary from one manufacturer to another due to a lack of standards?


    (Brief descriptions of the diagrams)

    A -- The DVD black to white scale 0-235 is evenly translated to the IRE scale 0-100.

    B -- 0 to 235 DVD values are slightly scrunched and evenly spread out over 7.5 to 100 IRE.

    C -- 0 to 16 DVD values are all output as 7.5 IRE and the rest of the range 17 to 235 is evenly translated to the IRE scale 7.5 to 100.

    D -- 0 to 16 DVD values are all output as 0 IRE and the rest of the DVD range 17 to 235 are evenly translated to the IRE scale 0 to 100.
  2. ChrisWiggles

    ChrisWiggles Producer

    Aug 19, 2002
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    Allan: Your B and D diagrams are the more correct ones, but the numbers are off. Black (digital 16) is output at 7.5, or at 0. BTB material is material defined below digital 16, so would be at voltages below 7.5 and 0 IRE. Using NTSC setup of 7.5 IRE output isn't defact clipping things, though certainly some players may clip in either or both setup situations.

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