The heart and soul of the program is the ZoneMapper. Based on Ansel Adams' Zone System, the ZoneMapper gives you exacting control over the amount and location of contrast in your photo. Represented by a black-to-white gradient, it works like this: Points on the gradient correspond to a smaller, grayscale representation of your image called the ZoneFinder, and when you mouse over the gradient, the corresponding zones in the ZoneFinder light up. To brighten or darken those tonal areas, simply click to create a handle, then drag it up or down on the grayscale to expand or contract the zones of the scale. Much more intuitive than Curves, you can make minute or grand adjustments very quickly.