04-06-2010 01:28 PM - edited 05-12-2010 02:02 PM
This is a really weird one... never seen behavior in an LCD like this before.
I've noticed that the screen steps down the backlight brightness, very slowly and you almost don't notice at first, when low contrast images are displayed on most of the screen.
I first noticed it while browsing, but the easiest way to reproduce the problem is to open two copies of Paint, maximize them, and make the image size fill the screen. Leave one of them all white, and fill the other one with all gray. Set your screen brightness to maximum. Now alt-tab between the two copies of paint every 10 seconds.
What I see is that when I leave the gray image on the screen for a few second, you can see the backlight brightness start to decrease in about 10 discrete steps over 3 seconds. When you switch back to the white image you are left with a dim looking screen, and then you can see as the backlight brightness steps itself back up over the next couple seconds.
You will notice the effect more with less ambient light, or by standing back and gauging the total light output from the monitor in a dark room.
To be clear, I'm not saying that one image is dimmer than the other. I'm saying if you leave it on the gray screen for a few seconds, and then switch back to the white screen, *after* you switch back, over the next 5 seconds, you will see the total screen brightness steadily increasing.
Sorry for the long winded explanation, but... am I seeing things? Or is this some new misguided "contrast-enhancing feature" of the LCD? Would really love to hear your experience.
Solved! Go to Solution.
04-06-2010 02:52 PM - edited 04-06-2010 02:53 PM
The same thing has been reported for the T410. You can see how to fix it here:
It appears to occur anytime you are on battery and the intel graphics power plan is set to anything other than 'maximum performance.' It's pretty subtle, but really annoying when it happens.
05-12-2010 02:01 PM
I found the solution here:
It's a power saving "feature".