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Just what is RGB?

Discussion in 'Televisions' started by Wayne Moule, May 5, 2002.

  1. Wayne Moule

    Wayne Moule
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    RGB has it's plus points in better very saturated colours,but you do lose natural lighting to a great degree.Take light reflections from metallic objects.In RGB the metallic nature is lost through RGB.

    Overall contrast is sometimes dulled and sharpness is lost.The luminescence of flowers is greatly reduced.

    So,just what is RGB?

    I think it's been mentioned before that it is a direct link to the Red,Green and Blue guns of a picture tube without any processing.Is this the case or does the signal go through any other circuitry at all?

    Thankyou for reading my rant.
     
  2. pwoody

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    Great someone else has noticed RGB ain't as sharp as composite / s-vhs. I use it for DVD as the overall picture is better than composite but don't for Digital Satellite as is picture sharpness suffers.
     
  3. Guest

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    Originally posted by pwoody
    Great someone else has noticed RGB ain't as sharp as composite
    --------------------------------------------------------------------------

    well I have never seen a better composite signal, than svhs

    am I missing something here????????????
     
  4. Squirrel God

    Squirrel God
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    The red, green and blue colour signals are kept separate in the cable (scart), resulting in reduced interference which in turn results in a better picture.

    RGB looks crap on some sets because they use preset defaults for RGB that you can't adjust (the real killer being contrast, JVC are particularly guilty of this). I used to have a Philips and the RGB picture was first rate compared to S-Video.

    I admit S-Video looks great, but if you want to really see the difference in clarity, try viewing text (e.g. from a DVD menu) using S-Video and RGB... IMO RGB is much clearer.

    It goes without saying that the quality of the picture is also affected by the quality of the cables you use - using fully shielded, oxygen free cables with gold connectors results in an even better quality picture (for all sources). I invested £35 in an IXOS scart cable and have never looked back (from HiFi Bitz, the cheapest I could find for IXOS scarts). I was skeptical about whether cables really made an improvement to picture quality but I have to say that it really does!
     
  5. Squirrel God

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    Also, don't forget that some TVs let you alter the sharpness setting on RGB input. If you can't adjust this, then if the preset sharpness setting is too low, then that might be the source of your angst!

    It's also worth bearing in mind that lots of people have their contrast set way too high - it should be set as high as you can go without blooming. If the contrast is indeed set too high, then you will notice a drop in contrast when switching to RGB, so you would have to knock the contrast back up to compensate (assuming you're allowed to do this).
     
  6. Wayne Moule

    Wayne Moule
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    As I've said before,S-Video on my 32PW6006 is better than RGB overall,from my Sony 725 DVD.Yes,I was pleasantly surprised.The text on DVD menu screens is rock steady in S-Video.
     
  7. Zacabeb

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    Another thing is that S-video and composite are often edge enhanced in order to make them stand out more.

    Then we have the 100Hz weirdness. 100Hz TV sets often compress color to a very low resolution in their digital processing. When using composite or S-video inputs, many sets will add color transient improvement (CTI) to sharpen the color - but with RGB inherently permittimg full color resolution, the circuit is defeated.

    The irony is that since the RGB signal went through the same color compression in the 100Hz processing, it would have done good to add some CTI. Not doing so makes saturated colors appear less sharp than with S-video. The actual color bandwidth is still a bit higher though, so fine details don't get desaturated as much as with S-video.
     

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