How important is 10-bit color, really?

[Penton-Man]

Originally Posted by Tech-UK

12-bit

Something that people on consumer forums seem not to understand, who have little or no background in the day-to-day workings of theatrical deliverables (https://forum.blu-ray.com/showthread...or#post9623181) nor much of any insight as to how/why ’12 bits’ was chosen by the D-Cinema working group back in-the-day is that the 12bit encoding thing was determined because of the D-cinema choice to use XYZ components…note that XYZ is over 2x the size of BT.2020 based on orthogonal linear basis vectors. This 12 bit depth determination by the D-Cinema working group is/was really rather straightforward as compared to determining the white point for Digital Cinema ….lessons from which were learned in helping with the recommendation for the white point for ACES.

For those who didn’t understand the chart and table posted at the bottom of the last page which is based directly on the work of the ITU investigators actually tasked with determining the parameter values of Ultra HD in ITU-R BT. 2020, in simplistic terms, think of it like this…if you weight the color space based on the original Rec. 709, then you should see that to extend to the wider gamut of BT.2020 needs about another bit…..not really as much as 4 bits (which would come to a total of 12bits).