I have an HP ZBook G2 laptop with a DreamColor screen, Nvidia Quadro K5100M graphics adapter, and Windows 10. When I bought the laptop in 2016, it offered multiple choices for screens and graphics adapters, and the DreamColor and Nvidia Quadro K5100M options were by far the most expensive options, so I thought I’d be getting the best image/video quality out of it.
But I have always noticed terrible video quality on this laptop when watching videos with dark scenes. The quality is a lot worse than an older ThinkPad T60 laptop from 2006 with Windows XP.
Here is an example showing the exact same video file on both laptops, playing in VLC media player, paused at the same place (these are photos of the laptops’ screens, not screenshots). The newer HP ZBook laptop looks like:
The older ThinkPad laptop looks like:
I also took this photo of the HP ZBook laptop duplicating its screen (on the left) to an external monitor (on the right):
As you can see, the gradations on both the older ThinkPad laptop and the external monitor look very smooth, while they look very rough/pixelated on the newer HP ZBook laptop. Apparently this phenomenon is known as "color banding".
Since the HP ZBook laptop’s output to an external monitor looks fine, that would indicate the problem is related to the ZBook’s DreamColor screen and not its Nvidia K5100M GPU.
It is extremely disappointing that the HP ZBook’s DreamColor screen, which was supposedly the best laptop screen one could buy at that time, looks so much worse than the ThinkPad screen, which is almost 10 years older. Are there any settings I can change in Windows 10 or the Nvidia Control Panel to have the HP ZBook’s video quality be more like the ThinkPad and external monitor?
I did see a setting in the Nvidia Control Panel for the "Output color depth", although I’m not sure if that would have any impact on this problem. Currently it is set to "8 bpc", and it shows a "10 bpc" option:
Unfortunately, when I change it to "10 bpc" and click "Apply", it automatically changes back to "8 bpc". I’m not sure why it won’t let me change it to "10 bpc". Everything I have read about the DreamColor screen and Nvidia K5100M tell me that they both support 10-bit color. But I don’t know if the ThinkPad with Windows XP supports 10-bit color – if it doesn’t, then changing the ZBook to 10-bit probably won’t help.
Additional information: I just tried booting up the laptop using a SliTaz Linux Live DVD to see if the problem also happens in a different operating system. I played the exact same video file, and although it is still pixelated in dark scenes, it definitely isn’t as bad as it is in Windows.