Light is the photographer's primary medium, and the time of day shapes its character. The golden hour—the first hour after sunrise and the last before sunset—delivers warm color, soft directional light, and long shadows, and is widely considered the best natural light for portraits and landscapes. The blue hour, the twenty to thirty minutes before sunrise or after sunset, produces even, cool light ideal for cityscapes and moody, atmospheric work. On overcast days, clouds act as a giant diffuser, producing wrapping, low-contrast light with minimal harsh shadows and no squinting—flattering conditions for skin tones.
Hard light comes from a small source and produces sharp shadows and high contrast, while soft light comes from a large source and yields gradual shadow transitions. The midday sun and a bare flash are hard; an overcast sky, a large softbox, or a north-facing window is soft. Light obeys the inverse square law: a source twice as far from the subject delivers one-quarter the light, or two stops less illumination, which is critical when positioning strobes and off-camera flashes.
Several classic portrait lighting patterns organize the way a face is illuminated. Rembrandt lighting places the key light at about 45 degrees from the subject, producing a triangle of light on the cheek opposite the source. Loop lighting, the most common flattering pattern, comes from a key light 30 to 45 degrees to the side and slightly above eye level, creating a small loop-shaped shadow from the nose on the cheek. Butterfly or paramount lighting places the light directly in front and above the subject, casting a small symmetric shadow beneath the nose and flattering facial symmetry for fashion work. Split lighting places the light 90 degrees to the side, lighting half the face and leaving the other half in shadow for a dramatic, moody effect.
Rim light, also called hair or edge light, is placed behind the subject to outline hair and shoulders, separating them from the background. A multi-light setup usually includes a key light as the main shaping source, a fill light to soften the shadows cast by the key, and a hair or rim light to lift the subject from its surroundings. Modifiers shape the light further: a softbox or window produces soft, wrapping light when large relative to the subject; a beauty dish—a shallow dish-shaped reflector with a center deflector—creates a semi-hard, semi-wrapping light popular in beauty work; a snoot narrows the beam to a tight circle for accent or background lighting; a honeycomb grid on a flash produces an even narrower spot. Feathering aims a softbox so the light falls off across the subject rather than hitting dead-on, controlling where the falloff begins. A reflector bounces existing light into shadows, with silver for contrast, white for neutral, and gold for warm fill. Catchlights—the specular highlights in the eyes—add life and dimension to a portrait, and their position follows the key light.