If you want full control over the calibration settings of the Sony X850C, select the 'Custom' picture mode. For playing video games, 'Game' is better, because the input lag is about 25ms lower.
The 'Brightness' setting doesn't have the same effect as the 'Brightness' setting on other TVs. This changes the backlight luminosity. We calibrate for a dark room, so if you have a bright one, increase it to the max.
'Black level' is the equivalent of 'Brightness' on other TVs. Do not touch this setting, or else you risk crushing the shadows.
See the Q&A section of our review to see what the Clearness slider does. Smoothness is the soap opera effect.
A sharpness of 50 means no sharpness added. It will slightly blur the picture if you lower it. As mentioned in our review though, there is no way to remove the sharpening on 720p and lower inputs. You might want to turn on 'Digital noise reduction' when streaming a poor quality video.
If you want to benefit from the wider color gamut, set 'Colorspace' to 'BT.2020'.
You can find above all color temperature settings. You will need to enter all of them, because they are all active at the same time. This adjusts the white balance for different shades of gray (10% to 100%).