[geocar]

HDR10 is 10-bits per component and there are plenty of 16-bit images that aren't HDR, for example: http://i.imgur.com/Wm2kSxd.png -- the main thing about using HDR is to increase the range of values, i.e. what the biggest and smallest values are, not merely how many distinct values you can represent.

[midasuni]

Well that’s just the colour space, you’ve also got the gamma curve to consider when you look at the perception of how something looks