I noticed pretty early into my time with the Nexus 7 that the screen is washed out (color saturation is diminished, brightness and contrast are increased) after watching video. This happened pretty much with all video apps, including YouTube, Play Video, and Netflix, and seemed to vary in intensity by what kind of video was played.
Turning the screen on and off seems to fix the problem until the next video, but I was wondering what caused the issue. My suspicion was that Nvidia’s Tegra 3 PRISM technology, which decreases backlight brightness and increases contrast and color saturation to reduce power, might be at fault here as I suspect it is in a number of screen issues on Tegra 3 devices.
Here’s how NVIDIA describes PRISM:
NVIDIA PRISM Display Technology – PRISM (or Pixel Rendering Intensity and Saturation Management) reduces a mobile device’s backlight power while simultaneously enhancing the pixel color to deliver the same visual quality with substantially extended battery life.
As it turns out, I might be correct. Some folks over at the XDA forums jumped on the issue and discovered a setting that can be changed that apparently resolves the problem. Doing so likely decreases battery life while playing video and, I suspect, at other times, but that’s the trade-off. Note that your Nexus 7 has to be rooted to apply this fix, and of course as always you do such things at your own risk.
Here’s the thread (the fix is on page 5) if you’d like to give it a try. I might do so myself, and if I do I’ll report back on whether it fixes this particular problem and/or other problems, and if it introduces anything new.
Update: Looks like this might also fix an LCD ghosting problem that some folks have experienced. If you have that problem, give this fix a try before sending back to Google. It just might save you some hassle.
Update 2: I unlocked and rooted my Nexus 7 and applied the fix outlined in the thread, and it did resolve the washed out screen after watching video. I didn’t notice any ghosting, and so I can’t comment on that issue, but some folks have indicated a fix there as well. The process of unlocking and rooting is pretty painless, with a very nice tool that you can find here.
Update 3: Steve in the comments mentions an app he created to toggle the fix on and off. You do have to be rooted, and I haven’t tried this app yet, but here’s the link if you want to give it a try.