Hdmi question

[invictius]

I have an 11 metre run (2 5m cables, a 1m cable with joiners in between) going to my plasma from my gaming PC and when I switch to it I get a sort of coloured ghost effect around some of the image for half a second or so. The colour is kind of the outline of the object which takes up the most space onscreen. Could this damage my tv?

[fraggle]

Kind of weird that you'd get analogue-like distortions when HDMI is digital. I can't see how it could damage your TV though.

[FireFish]

Kind of hard reasoning about what it could be when the only things mentioned
are TV, PC, Extension Cable...

https://www.google.com/search?nts&q=hdmi+ghosting+effect&oq=hdmi+ghosting+effect

[GreyGhost]

Depending on the quality of the cables you're using, the problem might be an old friend of mine - signal attenuation.

[invictius]

Here's what it looks like

[Moriarti]

If it only happens right after you switch inputs, it's probably just a thing your TV does and nothing to worry about. If the cables were bad, you wouldn't get any picture at all.

[flubbernugget]

Wouldn't attenuation cause a more "noisy" distortion?

[Moriarti]

HDMI is digital. It does not respond to noise the same way an analog signal would. If there's more error in the signal than it can correct for, then you won't get a picture. There's no fuzzy in-between state between good and bad signals like there is with analog.

[Maes]

That's not entirely true -it's possible to build-in some resilience and fallback capability into a digital signal, at the cost of increased overhead and complexity (e.g. switch between lower and higher bit/signaling rate signals) though it would be strange to use such a scheme for an indoors cable.

In any case, it looks like HDMI doesn't include such a scheme, but it's possible to get data errors by using long cables and/or dodgy connectors. In that case, the TV might detect the errors and try to "compensate" for them by replacing digital noise with some sort of filtering and blending with surrounding pixels -which will get you blurry images and "ghosting".