1.2. How We See the World

The human eye is an incredible thing. It can differentiate contrasts up to 1:10,000. That's a dynamic range of about 14 EV. But it goes even further: The eye can adapt to almost any lighting situation, stretching the total perceivable range to approximately 1:1,000.000.000.

Adaptation: For example, the sun is a million times brighter than candlelight. Still, we can see perfectly when walking in a sunny park, as well as inside of a church. Such extreme contrasts cannot be seen at the same time. When you step into the dark entrance of that church, you experience a short moment of blindness. Within seconds, your eyes begin to work: your pupils widen and your vision brightens up again. This physical reaction is called adaptation.