Lighting Design Principles
Lighting design is composition with light rather than simply making the stage bright. Its purpose is to create visibility, depth, and focus, and the foundation that everything else builds on is three-point lighting. The key light is the dominant source that reveals the subject and casts the shadows that define its form. The fill light, softer and coming from the opposite side, controls how deep those shadows go — the ratio between key and fill is what sets the contrast of the picture. And the backlight, from behind and above, rims the subject with light and separates it from the background, restoring the sense of depth that a flat front wash flattens away.
Angle, colour, and intensity are the tools you use to steer the audience's eye. A bright, warm, isolated pool of light pulls focus straight to a soloist while the rest of the stage falls into cool shadow. Contrast — light against dark, warm against cool — is what gives an image its shape, which is the real reason lighting everything evenly tends to flatten a scene into a lifeless snapshot.
A time-tested approach to lighting faces is the McCandless method, which crosses two key lights from roughly 45 degrees to the left and right, often in slightly different tints, to model a face in three dimensions. The thread running through all of it is the same: you light for contrast and for storytelling, shaping where the eye goes, rather than just pushing up the overall level until the stage is merely bright.
Light for contrast, not brightness.