This volume in the LIFE Library of Photography deals with the nature of light; the evolution of modern film since the early discoveries of light's effect on sensitive substances; the types of film now available and their uses; light meters and their operation in the determination of accurate exposure; sources of artificial light; and the creation of pleasing light patterns. These topics cover the basic problems faced in taking a photograph. By exploring them in orderly fashion this book shows how the technical objectives of a "good" negative can be combined with the aesthetic aims of an outstanding picture.