Why Red Push??????

Discussion in 'Archived Threads 2001-2004' started by AlbertH, Mar 7, 2002.

  1. AlbertH

    AlbertH Stunt Coordinator

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    Simple question, WHY do certain tv's have RED PUSH? If everyone hates it, then why do tv's have it!?!?
     
  2. Guy Kuo

    Guy Kuo Supporting Actor

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    Red push is necessary because humans are acutely attuned to flesh tone. If flesh tone is tinted incorrectly, people notice and complain. That problem automatically occurs if the display, like every single TV, comes from the factory with a too blue grayscale. If the display didn't have an opposing "error" in its color decoding to remove the blue tint from flesh tones, people would notice that skin looks too blue when the grayscale is too blue. The red push in the color decoder intentionally exaggerates anything with red in it and skin has red in its coloration. So you red push hides the skin color problem inherent with the too high color temperature that comes from the factory. Unfortunately, it also messes with everything else which has red in it and basically means that you get correct color for skin and only skin. People see that the picture is really bright and skin looks good so it MUST be a better picture. That means sales - exactly the goal of any good manufacturer.

    Now, we of the home theater enlightened want accurate color for the ENTIRE scene, not only flesh tone. In that quest we take the consumer display and have its gray scale brought back down to the standard D65 color of gray. This does not correct the red push built into the display to hide its normally severely too blue factory shipped state, so you start to notice that the greater amount of red in the correctly colored grayscale causes the red push to be evident. Remember, we originally had two opposing "errors" which combined together yielded good looking flesh tones. With the too blue error of a bad gray scale removed, red push becomes more noticable because skin tones are now too red. In the ideal situation, the calibrator is also able to adjust the color decoder to remove the red push. This is possible on some displays. Others, simply don't allow their color decoder to be corrected back towards NTSC standard behavior. In such cases, one can use an external R-Y attenuator (AKA red push attenuator in the forums) to correct the red push for component video. That works great for DVD, but the internal tuner will still yield too much red.

    In summary, manufacturers must build red push into the displays in order to make flesh tones look correct while still being competitive in the display brightness by boosting blue rat race.
     

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