Noise on screen

D

DITC

Limp Gawd
Joined
Mar 27, 2006
Messages
394
Just got a 22" BenQ ws and when I have a dark gray background on my desktop I can see some noise in the picture. Is this normal or... ?
 
Does the noise move? If so, it's probably the dithering used on TN panels to emulate true color.
 
Its think its normal if you're using VGA. My girlfriend's TN panel does it, but I never attributed it to dithering. Most LCD's have a "phase" adjustment when using VGA, which can lessen the effect. I think DVI resolves the issue.
 
Yeah, the noise moves, sort of like static when a channel ain't tuned correctly, but it's not that visible, and it's only really visible on certain colors... that being dark ones, but not on black, but slight lighter than black.

I only got a VGA cable from the monitor to my graphics card, but I've also tried it with a DVI adapter just to check the ports on the graphic card, but it was the same.
 
Won't matter what input you use, it's the monitor panel surface and the anti-glare coating used causing you to see this effect. Many, many monitors have the same issue.
 
The anti-glare coating doesn't move. :p

It's definitely TN dithering.
 
The light coming from the monitor interacts with the coating as it passes through and yes good observation, the coating does not move, but your head does. This issue is not limited to 6-bit TN dithering panels.
 
I'm almost certain that this particular issue is not a problem with the anti-glare coating. I can go over to my girlfriend's TN panel right now, and if I look up from below the monitor, so that the monitor darkens, I can easily spot the noise.

Your monitor should have adjustments called "clock" and "phase" in the OSD (only available through VGA). Play with it and watch your noise get better and worse. One of them is for horizontal frequency and one is for vertical.

Here's a test pattern: http://www.techmind.org/lcd/phasing.html
 
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