Tuesday, 14 August 2007

Improving SD picture quality on an LCD/plasma TV

Today I unpacked and connected up my shiny new LCD TV. After trying a couple of DVDs and Sky noticed some very irritating video noise. I'm not by any means a videophile and I'm not planning on paying extra for Sky HD but I wanted the best possible picture from my SD (standard definition) equipment.

What follows are some quick tips to get the most from a large screen HDTV with SD sources via SCART such as a DVD player or Sky box (non HD).

The first thing I did in Sky was change the video output mode from PAL to RGB. To get to this option press Services, 4, 1. This improved the image considerably.

Next I did the same on my DVD player, this time there were a couple of small switches on the back of the player. Again this helped but there were still some very distracting cross-hatching patterns which were really bugging me.

Whilst reading up on A/V connections I stumbled across the solution on Wikipeida. The SCART input socket on many TVs also acts as a composite video out and the unscreened wires in my bargain basement SCART leads produced crosstalk between the in and out leading to noise and ghosting. The solution to this was simply open the TV end of the SCART plug and cut the composite video wire on pin 19 (shown below). This prevents the superfluous composite signal being sent back down the cable.

The Wikipeida article suggests it may also be possible to push the pin back into the plug for future use but if you do choose this method don't forget to insulate it so it doesn't short across other pins.

After this modification the cable becomes one-way for composite signals so it's a good idea to label it to avoid head-scratching in years to come when plugged in the wrong way round.

Once I put the cables back I was pleased to see the noise had gone and the picture was much better. At least for the time being my SD setup will keep me happy until HD reaches a more mainstream price.

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