6 Replies Latest reply on Feb 4, 2015 9:00 AM by Dekken

    Problem with the screen brightness of my laptop (adaptive backlight, adaptive brightness, dynamic contrast, advanced contrast ratio issue)


      I have a problem with my laptop, below are all details. Please let me know about the causes of my problem
      and how to eliminate them.


      1) Dell Precision M6800 laptop (Intel HD 4600 graphics, Nvidia Quadro K3100M),
         switchable graphics (Nvidia Optimus technology) is disabled in BIOS;
      2) Windows 8.1 Pro x64, all firmwares, BIOS and drivers are the latest versions, all latest windows updates
         are installed (I performed a clean OS installation, then installed all necessary drivers, then installed
         all Windows updates, no additional software were installed);
      3) I always use "Maximum Performance" power plan with the following settings in its section "screen":
         -- turn off display (on battery: 10 min, plugged in: 15 min),
         -- display brightness (on battery: 85%, plugged in: 85%),
         -- dimmed display brightness (on battery: 85%, plugged in: 85%),
         -- enable adaptive brightness (on battery: switched off, plugged in: switched off);
      4) There is uniform dark grey background on the Windows desktop (this background might be any other
         dark color, uniform or not, without any bright areas).


      Display brightness changes in spite of the adjusted settings in active power plan. The problem exists
      in two cases only: (i) I work on battery; (ii) transition from battery to mains or vice versa. In case "i"
      display brightness increases when a bright object appears on the uniform dark grey background of my Windows
      desktop (for instance if you run notepad.exe and its mainly white window appears over the desktop) and
      display brightness decreases when the above bright object disappears from the uniform dark grey background
      of my Windows desktop (for instance if you close or reduce to the taskbar the notepad.exe window). In case
      "ii" display brightness decreases when you pull a power connector/plug off the laptop and increases when
      the connector/plug is plugged into the laptop again.


      This issue does not have a place if switchable graphics (Nvidia Optimus technology) is enabled in BIOS,
      and the laptop screen is driven by, I assume, Intel HD 4600 graphics. As I utilize on my laptop
      10-bit color depth workflow and correct color reproduction, it's much comfortable to work without
      switchable graphics. I tried all latest video drivers, from both the laptop manufacturer web-site and
      Nvidia web-site drivers including their latest beta-drivers, but the problem exists regardless of
      the driver version installed. There isn't the problem under Windows 7 Pro x64.