[edaly]

I'm getting a very strange effect with my new GeForce 6800 (Gainward Ultra 2100 128MB 'Golden Sample'):


When the amount of screen space covered by white increases, the overall brightness decreases.

http://www.golsat.com/edaly/50PHD7UY...Brightness.JPG


This is most visible on my plasma TV via the DVI output, so I originally thought it was some funky gain adjustment on the TV (even though everything was turned off).


Then I hooked the GeForce 6800 up to an old Viewsonic CRT using the VGA output and lo and behold, there it was. The effect was a lot less noticeable on a CRT, but it was still there. The higher the overall brightness of the monitor, the easier the effect is to notice.


Has anyone else seen this effect? Is my video card a lemon?


BTW, an easy test for this problem is this: go to your desktop and open a window with a white background (e.g. Windows Explorer). Grab the mouse and resize the window so it's super small, then rapidly resize it until it's almost full-screen. While doing this key your eye on a static portion of the screen like the title bar of the window.



edaly

 

[jimwhite]

that's perfectly normal for consumer grade displays.... it's a result of poor or non-existent load-regulation in the HV Power supply....

 

[maxleung]

Interesting...I thought this only happened on old CRT directview displays with bad (by design) powersupplies!


What drivers are you using for the 6800? Also, is there some option in Display Properties for the card that may be inadvertantly enabled?

 

[ferrisg]

Usually poor high voltage supplies on TVs show up as geometry distortions with high white content, not diminshed white level. I think somebody in the plasma forum (or maybe elsewhere in this forum) mentioned it before and there was some weird setting on the plasma causing this (it was a form of burn-in protection). I don't know what would cause it on the CRT, though. I don't think anyone ever found out if it was really a function of the video card.

 

[jimwhite]

nooooo, poor HV regulation is just that.... more white, more HV current.... more HV current, less HV... less HV, less brightness.... quite common...

 

[RichB]

This could be caused by the plasma settings. Check out the menus for power saving modes.


-- Rich