Book excerpt: From a master of professional photography, a book that explores the exciting possibilities of artificial light. This guide to on- and off-camera flash picks up where Peterson's previous title, Understanding Exposure, left off--helping free photographers from the limitations of auto to get the images they want when natural light isn't enough. For the many amateur photographers afraid to venture past natural lighting, here is the book that will finally help them master artificial light. In his trademark easy-to-understand style, Bryan Peterson explains not only how flash works, but how to go beyond TTL automatic flash exposure to master manual flash, allowing readers to control the quality, shape and direction of light for a perfect exposure, every time.