III. light “direction:”
In life, and in the real world, light often has direction. What is direction? Direction is suggested by shadow, and it’s shadow which helps to create form. Form consists of visual cues which describe shape, volume, and depth. In fact, the subtle shadow in the photo below is called a “form shadow,” and the direction of the gradient from light to dark shows that the light source is coming from the left.
(to be continued . . . )
Whether it comes from the sun when it’s low in the sky, or from an incandescent lamp sitting on a desk, the light comes from “somewhere.” That “somewhere” suggests a lighting concept known as a “motivated source.” More of a cinematography term than one familiar to still photographers, a motivated source is when a particular light falling onto your subject comes from either an actual or suggested, real-world source. Now, there are may be images in which the light has no real motivation, i.e., no real or suggested “natural” source, and that’s fine, too. In the photo below, the light is “motivated” by the computer screen, and also happens to be the actual source of illumination in the shot:
In traditional beauty lighting, the source is often centered, just above the lens, the objective being to fill-in all the crevices in the subject’s face from the point of view of the camera’s lens. For example, in this ring-light shot, the light has one of the least form-creating direction, where the light is coming directly from the camera: