Originally Posted by Silencers
I've used Spears&Munsil disk on XB1 yesterday with the same result, both black and white have been clipped severely, I couldn't see any bars beyond 231 for whites, and nothing below 17 for blacks. I've messed around with settings for quite some time, before I changes output from PC (RGB full) to TV (RGB limited), and then immediately I could see everything that was clipped before. To me this doesn't make sense, I would expect this to be the other way around.
When the TV is set to "RGB Limited" (the norm), Black is 16, and White is 235. These are "Video Levels".
When the TV is set to "RGB Full", Black is 0, and White is 255. These are "PC Levels".
When a video device is outputting "Video Levels" (the norm), the video is output unaltered. It can contain RGB values < 16 and > 235. The AVS HD 709 bars contain the values they are labeled with.
When a video device is outputting "PC Levels", it expands Video Levels to PC Levels. This means replacing values < 16 with 0, values > 235 with 255, and scaling the values in the range [16, 235] into the range [0, 255]. The AVS HD 709 bars do not contain the values they are labeled with; instead, they reflect this expansion.
The TV setting and video device setting must match. Both should be using either Video Levels or PC Levels.
When using Video Levels, you should adjust Brightness on the TV so that Bar 17 just flashes, and Bars 16 and below are deepest black, blending into the background. You use Contrast to set the white level, and you should see flashing at least up to and including Bar 234, though it's OK for higher-numbered bars to flash.
When using PC Levels, you will never see bars < 17 or > 234 flash for reasons already given. The "blacker than black" (BTB) and "whiter than white" (WTW) values have been crushed to 0 and 255, respectively, and you can't use them to help you set Brightness and Contrast.
When you have a levels mismatch, what you see depends on who's using what. When the TV is at Video Levels and the video device is PC Levels, there will be black and white crush. The picture will look darker and super-saturated. When the TV is at PC Levels and the video device is Video Levels, the picture will look gray and washed out; on AVS HD 709, you will see Bars < 17 flash.
Another wrench is that some devices can artificially clip BTB and/or WTW when using Video Levels.