The DSLR Field Guide

Creating HDR Images

High dynamic range imaging, or HDRI, is a relatively new way of capturing the entire range of tones in a high-contrast scene, from shadows to highlights, which is beyond the ability of a normal sensor to capture with one shot.

For instance, a typically bright, sunlit scene containing highlights and shadows has a dynamic range in the order of 2,500:1, and while the human eye can accommodate this (though it does it by scanning the scene rapidly and building up a cumulative image), a digital sensor cannot completely manage it. This is because, while a typical 12-bit sensor shooting Raw theoretically has a dynamic range of 4,000:1, its practical range is closer to 1,000:1, mainly because of noise. If the sun appears in the shot, ...