A second light source — usually called a fill light or fill flash — can greatly improve portrait lighting. It reduces the depth of shadows and softens the appearance of facial features, amongst other traits. Best of all, a fill light is easy to create: either a simple on-camera flash or a reflector is often sufficient. However, a second light source can just as easily harm portraits. This tutorial therefore focuses on how to control the location and intensity of the fill light in order to produce a desired portrait appearance.