[mythtv-users] KDL52XBR9 display problems
mythtv-list at dinkum.org.uk
Mon Feb 22 18:45:05 UTC 2010
On 22 Feb 2010, at 02:56, Christopher Kerr wrote:
> It's called Overscanning, and it was a feature back when analogue TV
> was prevalent, because the edges of the picture were often distorted.
> Overscanning allowed these flaws to be hidden.
As a trainee TV Technician, quite some time ago, I was told it was all due to valve TV's!
When the mains voltage dropped at peak demand times the picture got smaller due to no or bad regulation in the power supplies. The overscan was to ensure that the viewer never saw a black border around their picture or the wobbly edges due to cheap geometry correction .
> Now it's largely pointless and quite annoying.
Never mind archaic in the context of exact pixel flat panels, really don't understand how it got included in the HDTV specs, although interlacing made it in too!
Thankfully some broadcasters and originators are starting to ignore it for their HD output, shame the TV manufacturers aren't. I refused to buy any TV that didn't have 1:1 mapping but it's annoying if you didn't know about such things before buying a TV.
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