HDR Photography By Jakub Kubica

Nonetheless, now the focus is shifting from spatial to tonal resolution and this is the point where high dynamic range imaging enters into the scene. In fact, arguably it can be said that tonal resolution is more important than spatial resolution for image processing tasks.
The human perception of brightness is well approximated by a Steven's power law, which over a reasonable range is close to logarithmic, as described by the Weber–Fechner law, which is one reason that logarithmic measures of light intensity are often used.