BBC High Definition test card
If you have a HDTV with Freesat or Sky HD, you may need to adjust your set or amplifier to get the best possible HDTV picture.
The BBC HD channel now provides a testcard and audio signal to help you do this, see A Christmas Present from the HD Channel! BBC Internet Blog.
But, as they point out, DO NOT leave the test card on screen for more than 2 minutes if your screen is less than three months old or more than 5 minutes on older screens. Make sure you go back to the promo for several minutes before using the test card again.
I believe it was a widespread myth for a while that transmissive displays like LCD weren't subject to burn-in - or rather image persistence, as it should more accurately be described - but in my view it would really be more precise to say that they are less subject to burn-in, as the words ?EUR~on the whole?EUR(TM) in the last line of your kind response imply.
The effect with LCD displays is similar in appearance to CRT burn-in and is the result of the constant voltage produced by a static image causing the crystal voltage-response curve to change, which results in them letting more (or less) backlight through when compared with surrounding pixels. OK, technically it?EUR(TM)s not burn-in but the effect, which can occur after just a few hours, is very similar.
There are several things you can do to effect some sort of ?EUR~cure?EUR(TM) for image persistence (just Google!) ?EUR" but at the end of the day prevention is better. Whilst screen dimming will help reduce burn-in with the old CRT displays, dimming or darkening an LCD backlight won't help preserve your pixels!
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