T420 Auto-Dimming on dark web pages?

My T420 will auto-dim the display when I navigate to a web page that has a dark background, such as the Steam store. Then, when I go back to my desktop, open a folder, or go to a light-colored page (such as NBR), the screen will noticeably get brighter. The on-screen notifier for brightness will stay the same, but the brightness levels "fade" to darker or brighter.

This happens when my power plan is either on Max Battery or Energy Saver, so I know it has to be something with the power plan settings, but I haven't figured out a way to disable the dimming. Anyone else have this problem?

 

Likely a graphics driver thing. For AMD, it's called "VariBright," and I assume Intel GMA has something similar. Check the Intel Graphics settings, especially under the power settings, and see if you can find anything similar.

 

Intel Graphics Properties > Power > Deselect Automatic Display Brightness (it may be deselected by default when plugged in but also check the battery profile).

John

 

Still doesn't fix the issue. I disabled all the Intel display utilities from starting up because they kept resetting my color calibration profile at startup.

I think I may have solved it by changing the settings in Power Manager. There are options to auto-dim after a certain time, so I just disabled them, hoping they would do something.

Thing is, it's not a timing issue, it's a content issue. It used to auto-dim on dark webpages, not just after 2 minutes. Odd.

 

Definitely the Intel control panel. You'll need to change the setting even if you have the startup entries disabled; it's a driver level setting.

 

Right click -> Graphics properties -> Advanced -> Power Option -> Make sure that the powersource is On battery and display power saving technology is disabled.

 

Maybe it's the dynamic contrast enhancement setting on this property page?

 

I fixed this a while ago by using the stock video driver from Intel when I did a clean Windows 7 install on my mSATA drive. The Intel driver is significantly better than the Lenovo driver, and I've had no problems since.

 

I know this is an OLD thread.. but I'm experiencing this same auto-dimming on dark web pages on my W701.

My W701 has an Nvidia 3800m so it isn't an Intel graphics driver issue.

Any help will be greatly appreciated!

 

Check your GPU's power settings and dynamic contrast settings; the option for this "feature" is usually included in one of those two places.

 

Thanks for the response!

I've checked in the Nvidia Control Panel and there aren't any settings remotely resembling these. It is immensely annoying to have the monitor automatically dim when visiting a dark page (like www.blackle.com)!

Any other ideas, please? I've already updated to the latest versions of Power Manager, Power Management Driver, and the Nvidia video driver for W7-64 bit.

 

Yeah, I don't have an Nvidia GPU, so I don't really know specifics. No menu options as described in the last post here?

 

Hi,

thanks for the response.

I do have the options under 'Power Options', but the dimming it refers to there is the one that occurs after a set period of time - and not the dimming that automatically kicks in when the displayed items on the screen are dark.

And there's nothing in Nvidia Control Panel that remotely resembles these options either.

It only happens on my W701 which I think has a very different screen from my other Thinkpads.

At this point I'm assuming it's some kind of hardware feature in the display panel, that I don't know how to access via software. Any other input would be greatly appreciated!

 

Hmm. Usually this sort of feature is enabled/disabled in the GPU control panel settings for laptops (AMD VariBright, Intel adaptive contrast enhancement, etc), although desktop monitors do have separate dynamic contrast settings you can adjust.

The W701's monitor is a "normal" TN display, although I think it is high-color-gamut. At this point, I would see if you have the latest Lenovo display driver (as in for the screen, not GPU) installed for the W701.