1080i Overscan?

Discussion in 'Playback Devices' started by Matt Thompson, Apr 15, 2006.

  1. Matt Thompson

    Matt Thompson Stunt Coordinator

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    Oi. A few months back I jumped into the upconversion department and picked up a cheapie Cyberhome 550. I know, I know... I get what I pay for. Anyway, I tested it at both 480p and 1080i levels. The 1080i looks fantastic -- much better color levels and a crisper, clearer image. There's one simple problem: overscan.

    When played in progressive scan, overscan isn't an issue. I lose the basic 3%, of course, but other than that it's fine. But when I park the player in 1080i mode, suddenly the image takes up so much more of my screen. The black bars are smaller and I'm losing noticeable information to the left and right of the picture.

    Any ideas on how to configure the DVD player, or the TV itself? I've played around a bit in the service menu to no avail.

    For reference, the TV is an RCA D52W20B.
     
  2. ChristopherDAC

    ChristopherDAC Producer

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    I believe you will find this is a CRT projection unit. That being the case, more than likely the HV [final anode voltage] is derived from the flyback transformer. This means that you will have to recalibrate your display for the higher resolution, because the higher horizontal frequency means more voltage delivered from the power supply. You can see the same thing in action on a computer monitor when you switch resolutions. Also, I'd suggest adjusting the brightness [black-level] and contrast [white-level] values, which will also be thrown out of whack.

    Now, one wouldn't think the difference between "480p" [1050 Hz] and "1080i" [1125 Hz] would be that big, but there's probably something odd in the equipment somewhere. If my hypothesis is correct, 720p would be even worse than 1080i: do you have any way to test that?
     
  3. Matt Thompson

    Matt Thompson Stunt Coordinator

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    The television only supports 480p/1080i. 720p looks something like three tall rectangles squished together. Interesting, to be sure.
     

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