Key Light

Definition

The Key Light (German: Führungslicht or Hauptlicht) is the dominant light source in a film scene. It defines:

• The direction of the main light incidence
• The character of the lighting (hard/soft)
• The mood of the scene
• The modeling of faces and objects

Position and Angle

Horizontal Angle (to the camera axis)

Vertical Angle

Quality of the Key Light

Hard Key Light

Characteristics:

• Point-like source (Fresnel, HMI, sun)
• Sharp, defined shadows
• High contrast

Effect:

• Dramatic
• Energetic
• Confrontational

Soft Key Light

Characteristics:

• Large light source (softbox, bounce, silk)
• Soft, gradual shadows
• Lower contrast

Effect:

• Flattering
• Gentle
• Natural

Classic Key Light Positions

45°/45° (Hollywood Standard)

• 45° lateral
• 45° elevated
• Classic portrait lighting

Rembrandt Light

• Key far lateral (60-70°)
• Creates a triangle of light under the eye on the shadow side
• Named after the painter

Butterfly / Paramount Light

• Key frontal, strongly elevated
• Symmetrical shadow under the nose
• Classic glamour lighting

Split Light

• Key exactly 90° lateral
• Half face in light, half in shadow
• Dramatic, mysterious

Motivation of the Key Light

Professional lighting setups motivate the key light through visible sources:

• Windows: Natural daylight
• Lamps: Practical light sources
• Fire/Candles: Warm, flickering motivation
• Screens: Cold, technical motivation

Key Light in Practice

Setup Sequence

1. Position the key light
2. Evaluate its effect on the subject
3. Analyze the shadows
4. Add fill light (if needed)
5. Supplement with backlight
6. Fine-tuning

Typical Mistakes

• ❌ Key too frontal (flat)
• ❌ Key too high (eyes in shadow)
• ❌ Key too hard for a soft scene
• ❌ No discernible motivation

See also

• Fill Light
• Three-Point Lighting
• Hard Light
• Soft Light