The HDRI Handbook 2.0

Foreword

Though one could argue that the image is a human invention, high dynamic range is not. Light spans an enormous range, and our eyes can adapt from the dim level of a starlit night to intense daylight, spanning over eight orders of magnitude (100 million to 1). This is comparable to the energy difference between getting going on a bicycle and taking off in a jumbo jet.

With this kind of range in real-world illumination, how have we gotten by so long with image contrast ratios of less than 100 to 1? The answer is deceptively simple. Although the range of light is enormous, our brain cares most about reflectance, and its range is comparatively modest. In fact, it is very difficult to create a surface that reflects less than 1 percent of ...