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I just got a new video card (AMD ATI Radeon EAH5450) and new monitor (Dell E228WFP). Overall they work great except black pixels over a light-blue or gray background (e.g. text on a light background). In that case, pixels above and to the left of each black pixel are much lighter than other pixels in the background. The same problem doesn't happen for pixels to the right and below each black pixel-- only pixeles above and left are affected.

Here's a picture (taken using a digital camera pointed at the screen, and then magnified) to show what it looks like. See how the pixels above and left of each black pixel are lighter than pixels below and to the right of each black pixel? This is deliberately non-anti-aliased text so I can illustrate the problem more directly.

one letter and one color

Is there a driver setting I can use to stop this from happening? I'm assuming it's a driver problem and not a monitor problem, although this may be an invalid assumption.

When I take a screenshot and blow it up I see solid pixels-- whatever color distortion is happening is happening at the driver level or otherwise underneath what Alt+PrintScreen can see. The problem may be limited to some background colors-- for example a darker green background doesn't cause the problem.

To illustrate further, I screen-captured some non-anti-aliased text, blew it up 300% in a graphics editor, and changed the background color. You can see that the row of blue pixels over the horizontal line exhibits the lighter-pixel problem (although it's more subtle than the other screenshot because the magnification is less). Note that the green pixels above the text don't exhibit the problem-- they aren't any lighter above black pixels.

enter image description here

Here's more info about my environment:

I'm connecting to the monitor over a DVI cable and the monitor shows that it's a digital signal.

I'm running the latest available ATI Radeon versions:

  • Catalyst Version: 11.8
  • 2D Driver Version:
  • Direct3D Version:
  • OpenGL Version:
  • Catalyst Control Center Version: 2011.0728.1756.30366

I'm running Windows Server 2008 R2 with the "Desktop Experience" feature turned on so I can run Aero themes.

share|improve this question
Does the display have any settings related to clock, phase or sync? if so might be worth a play. If the link was analogue I'd suspect the cable. – Linker3000 Sep 2 '11 at 1:01
Nope. For digital inputs, the only settings available on the monitor are for color and brightness/contrast. Changing either of those has no effect on the shadow behavior. – Justin Grant Sep 2 '11 at 2:39

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