Peterson stresses the importance of metering the subject for a starting exposure, and then explains how to use various exposure meters and different kinds of lighting. The book contains lessons on each element of the exposure-aperature, shutter speed, iso-and how it relates to the other two in terms of depth of field, freezing and blurring action, and shooting in low light or at night. A section on special techniques explores such options as deliberate under- and overexposures, how to produce double exposures, bracketing, shooting the moon, and the use of filters. Understanding Exposure demonstrates that there are always creative choices about how to expose a picture-and that the decision is up to the photographer, not the camera.