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iscan HD problem

Discussion in 'Projectors, Screens & Video Processors' started by vancouver, Feb 20, 2005.

  1. vancouver

    vancouver
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    I do the test patern for Geometry and have got the outer most white box to be on the exact last pixal all the way around the screen. I assumed that when a video source goes through the iscan onto the plasma it would then fill the screen exactly. But when I watch SD TV for some reason the picture does not for all the way over to the left side of the screen. about 8 pixels are black...why?
     
  2. Pottsy

    Pottsy
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    Increase the overscan setting on the Iscan.
     
  3. vancouver

    vancouver
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    It only happens on some of the channels not all of them.
     
  4. PhilB1234

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    It's an issue with the broadcaster then. On Sky's football coverage I notice that some camera angles have an issue with an offset picture when (by using the iScan's overscan adjustment) everything else is perfect to the egde of he screen.
    Occasionally it happens for another channel but generally is perfect. I'd say in this instance you need to find a 'best fit' that works well for all channels.....
     
  5. Jasonjo

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    I have to have a slightly larger "coverall" overscan setting of 4 or 5, as some of the NTL music channels broadcast slightly differently...

    As said by Phil, you may need to go for a best fit or coverall

    JJ
     
  6. Pottsy

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    Vancouver,

    It's because you are seeing stuff that the broadcaster does not intend you to see. So sometimes there is program material in there, sometimes not. If you set overscan to about 5, you are still seeing a bit more than you should do, so no problem.
     
  7. vancouver

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    Does overscan not degrade the picture quality?
     
  8. Jasonjo

    Jasonjo
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    Don't ya trust me??? :cool: ;)
     
  9. Pottsy

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    Imagine the overscan function zoomed the picture hugely. Quality would drop.

    Imagine the overscan function shrunk the picture to tiny size. Quality would drop.

    So set it correctly, and quality is optimal. Setting it to include a picture frame of black bar(s) is just wrong! Unless you like to see stuff not intended for your viewing.
     
  10. vancouver

    vancouver
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    If an overscan is a "zoom" then any amount of overscan reduces picture quality to some degree.

    I am still not 100% happy with the iscan HD. I was watching Gataca superbit version and saw "pixels" in the white and blue...could be the movie, but superbit should be great.

    If you have the iscan set to the native resolution in my case 1024x768 is that a progressive signal or interlaced?
     
  11. Pottsy

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    Vancouver,

    I think some of this video stuff is getting the better of you... Firstly, go and have a read of some of the FAQ's here:
    http://www.yubyub.net/scalerfaq/scaler_faq_index.htm

    You'll find lots of technical info that answers many of the questions you are posting here, including your question about pulldown. You may get answers with a different bias on this UK forum, you may be better off asking on a US forum, like http://www.avsforum.com . We use different video standards here.

    If you set your HD up to XGA, and then follow the procedure here
    http://www.avforums.com/forums/showthread.php?t=185509
    then you are done. If you leave your overscan at 0 you are losing image quality by being too far zoomed out. If you set your PC monitor to show the same image, but smaller (leaving black bars around the image/desktop), do you think the quality will improve?

    The reason you bought an Iscan is for it to scale and deinterlace. Deinterlacing is turning an interlaced signal into a progressive signal, so yes, all outputs are progressive.

    Your DVD problem may be solved by a better DVD player, but it would be worth playing that DVD in another system first, just to check.

    Best of all, get an ISF qualified calibrator in to set your system up for you. Even the "experts" here cannot achieve what they do.

    HTH
     

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