Possible Grayscale and/or Red Push problem. Advice requested.

Discussion in 'Archived Threads 2001-2004' started by James Zos, Mar 7, 2003.

  1. James Zos

    James Zos Supporting Actor

    Joined:
    Jan 7, 2002
    Messages:
    725
    Likes Received:
    0
    Trophy Points:
    0
    The grayscale on my 7-year-old 27-inch Pansonic is finally at a more or less acceptable state. After endless tweaking misadventures I was finally able to get rid of a persistent, subtle yet oh-so-annoying greenish hue.

    One problem, however remains, and has been with my set as long as I can remember.

    When peoples' faces are in shadow, or, in other words, at the darker end of the scale, they turn a dark or at times bright red. Instead of the natural looking skin tones I get when someone's face is evenly-lit, they look unnatural, nearly beet red. It is almost like red push, but primarily, as I said, when faces are deeply shadowed.

    The problem goes away when I crank up black level (IE contrast) but then of course I end up with a washed out picture.

    Does this indicate a problem with R-cut? Why would it only show up in this way, if it was a general R-cut problem?

    As always, any well-intentioned advice, is greatly appreciated.
     
  2. Greg Kolinski

    Greg Kolinski Second Unit

    Joined:
    Oct 13, 2002
    Messages:
    331
    Likes Received:
    0
    Trophy Points:
    0
    I have run into some problems like that with my JVC WP56,and I believe most of it is due to "every" cable/satilte./OTA channel is different,as the NTSC term(never the same color twice)[​IMG] .I can watch FOX NEWS and every thing is perfect,then go to TNN and watch Star Trek TNG,and it looks like Picard had a really BAD tanning booth experience,almost like a lobster[​IMG] .Does this problem seem less when watching a DVD?Like I said I think a lot of it is from none of the channels are singing out of the same songbook,so to say.

    Greg
     
  3. James Zos

    James Zos Supporting Actor

    Joined:
    Jan 7, 2002
    Messages:
    725
    Likes Received:
    0
    Trophy Points:
    0
    "Does this problem seem less when watching a DVD?"

    No, unfortunately that is when it is most noticable. As far as broadcast TV, we just have a crummy antenna and poor reception so it all looks bad anyway.

    With the other-wise crystal clear picture on DVDs, it really stands out, whenever someone's skin isn't well lit or is only partially lit.

    I will say that I have seen some screen captures from other HTF members posted here and at least some of them seemed to suffer from the same problem, so maybe I just notice it more?

    Thanks for responding, Greg!
     
  4. Jeremy Anderson

    Jeremy Anderson Screenwriter

    Joined:
    Nov 23, 1999
    Messages:
    1,049
    Likes Received:
    0
    Trophy Points:
    0
    DRVS are used to set the white balance at high levels (i.e. 100 IRE), whereas CUTS are used to set the white balance at low levels (i.e. 20-30 IRE). Use Avia or VE to bring up a 20 IRE window and see if it appears reddish to you.

    A good way to make sure it's a grayscale problem without Avia or VE is to pop in a black and white movie and see if the shadow details appear to be tinted toward red. For instance, you could use the B&W parts of the movie Pleasantville, which have been digitally desaturated to B&W. Another one done this way is The Man Who Wasn't There.
     
  5. James Zos

    James Zos Supporting Actor

    Joined:
    Jan 7, 2002
    Messages:
    725
    Likes Received:
    0
    Trophy Points:
    0
    "Use Avia or VE to bring up a 20 IRE window and see if it appears reddish to you."

    I've tried this Jeremy, and it doesn't look reddish to me.

    "Another one done this way is The Man Who Wasn't There."

    I had a chance to pick this up used for nine bucks, and now I really wish I had. It's a good movie even if I didn't need it for this test...

    The strange thing about the problem I'm describing is that it doesn't seem to occur with anything BUT fleshtones. Take the movie Memento, for instance. The lead charachter will walk into his hotel room, and while his face is in shadow, it looks dark red, but when he steps into the light from a window, his skin tone looks natural. At the same time, other objects in shadow will not look red.

    It is definitely connected to black level in some way, because skin tones become normal when black level is cranked up...

    I wonder if it is not connected to the color decoder as well? A kind of red push, but only in shadow?
     
  6. Qui-Gon John

    Qui-Gon John Producer

    Joined:
    Oct 2, 2000
    Messages:
    3,527
    Likes Received:
    0
    Trophy Points:
    0
    This is so hard to get right, especially for all sources. I've been tweaking my grayscale settings recently. Just yesterday I watched the following all on DVD. The Generals' Daughter, nearly perfect color, a few times faces seemed a bit red, but not bad. An Episode of 24 Season 1, had a slight greenish hue for many low IRE scenes and a bit of purple tint in some scenes on black skin, Palmer and Keith, for example. Then I watched The Ring, the movie had many scenes that appeared way to green.

    But most of my 'mainstream' movies appear nearly perfect, like The Generals' Daughter did.

    Then when you throw in other source, cable, tape, who know what you're gonna get.
     
  7. James Zos

    James Zos Supporting Actor

    Joined:
    Jan 7, 2002
    Messages:
    725
    Likes Received:
    0
    Trophy Points:
    0
    John, I've thought of the possibility that some of this may be flaws with the DVD themselves, but I find it hard to believe that major releases like Memento would exhibit them. I'm going to get a DVD drive for my PC and that way I'll have something to compare my TV too, picture wise, for each DVD. I think it may be useful tweaking grayscale too, if I was to set my monitor next to my TV, since my monitor's grayscale is far better than my TV's, and it has a 6500k setting to boot.
     

Share This Page