When viewing this on a macbook air, the discussion around the two images in the section "Light emission vs perceptual brightness" appears weird. To me, the first image appears linearly spaced and in the second image I can hardly make out the difference between the first few bars of black.
Imagine there is a light source farthest to the right. Which bar would accurately reflect how you expect the light to decrease from the source? It should be the second (linear) bar, that the difference between the last few levels of black is imperceptible could be attributed to the fact that the MBA has a quite poor screen.
