Red Push and AVIA on Sony

Discussion in 'Displays' started by brandon_, May 11, 2006.

  1. brandon_

    brandon_ Agent

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    Need some help here. I have a Sony KDFE55A20 which I recently calibrated with AVIA--supposedly. My biggest issue with this calibration DVD is the lack of color adjustment. I do everything asked by the DVD. Color is adjusted properly and the hue is good as well. However, the flesh tone colors on faces are rosie. To compensate, I adjust the hue to a greener level, and lower the color. Problem; dull colors and greener hue. Any way to get into the service menu and adjust the red push...without purchasing manual?
     
  2. ChrisWiggles

    ChrisWiggles Producer

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    If your display has incorrect color decoding, the best thing to do is to fix the color decoding if possible.

    Second to that if you can't fix your display, you can reach a compromise color setting. You are incorrect at adjusting color balance to compensate for red push. Instead, go back and use the color bars to properly align the color decoding using the blue reference as well as possible. This will put you back to where flesh tones appear too reddish.

    Now, using the color decoder test pattern (which measures the % of push for red), lower color saturation slightly until red push is less. You may want to experiment a bit with content to reach a good compromise of good flesh tones while not under-saturating other colors too much. You do not want to touch the color balance adjustment while doing this, leave that at the setting you previously discovered.

    And of course, never attempt to resolve this problem by adjusting R gain.
     
  3. Gregg Loewen

    Gregg Loewen Video Standards Instructor, THX Ltd.
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    hi guys

    Chris, the problem with your soln is that the Sony LCD primaries wont match the filter colors so setting it using the color decoder adjustment and filters will not work. However, it will work like a charm for crts :)

    Best to set color by eye, off of a known reference image.

    Regards

    Gregg
     
  4. ChrisWiggles

    ChrisWiggles Producer

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    Really?

    That's quite odd actually, I've not run into a display where regular filters did not yield pretty good results. But then again, I didn't look up what kind of display that was and I haven't done much with LCDs in a while.
     
  5. Gregg Loewen

    Gregg Loewen Video Standards Instructor, THX Ltd.
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    yeah....my last training class, I used a Benq 8720 (which BTW is a bful PJ).

    On a scale of 1-100 the color was set at around 75-80 using the blue filter. When done by eye and using Jennifer off of VE (Title 18 Ch 23) the color was closer to 55-60. Visually there was a huge difference.

    Taking this one step further...and using a signal generator to calibrate HD. Find the offset difference between filter and by eye. In the above example the difference was - 20 from the filter. So in HD, calibrate using the filter, then take -20 off of that to accurately set HD.

    regards

    Gregg
     
  6. ChrisWiggles

    ChrisWiggles Producer

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    Can you compare with a display that uses a blue-only mode? Don't mean to dismissive, it's just the by-eye thing seems dubious unless I'm there in person. A difference of 20 seems like a HECK of a lot.
     
  7. Gregg Loewen

    Gregg Loewen Video Standards Instructor, THX Ltd.
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    A PJ with a blue only mode is PERFECT for setting color and tint. I love the BQ and and Optomas that have this. I have a Panasonic industrial in my classes to demonstrate this.

    I demonstrated this in January at the CES ISF Training Class using the Runco LCD panel. The results of the blue isolation vs filter were significant (ie: more that 20% difference).
     
  8. ChrisWiggles

    ChrisWiggles Producer

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    Just out of curiousity, these are the regular Avia filters you were using?

    And definitely blue-only mode is always preferable where available.

    At this point though, I personally feel uncomfortable recommending not using the filters, because even if they don't lead to the most precise results, I think a lot of novice users would have even less precision doing this by eye.

    I've not come across a display where filter versus blue-only mode was more than a click or two different, though you deal with many more displays than I do.
     
  9. Gregg Loewen

    Gregg Loewen Video Standards Instructor, THX Ltd.
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    oops, one more thing.

    Even if you can do blue isolation, and then nail color and tint, you may still have to turn the color down (or up) to make flesh tones look appropriate, depending on the accuracy of the color decoder channels for red and green.

    The only way to nail everything (as you know) is to do color isolation for each of the primaries, then to have complete color decoder controls available for adjustment.

    As a side note, Lion AV is sponsoring a Joe Kane class at CEDIA this year. It will be a 4 hour advanced class on color space and then color space management. We will be demonstrating CSM on several Samsung displays, Pioneer Elite Plasma, and a Sharp LCD panel (and or Hitachi panel).

    More and more manufacturers have been implimenting CSM settings. These settings are confusing at best. Our hope is to impart a method of scientific standardization of CSM management when performing a calibration.

    Regards

    Gregg
     

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