How does film lighting work?

A film set is dark until someone decides where every shadow falls. The key light makes the shadows, a softer fill lifts them, and a back light outlines the hair and shoulders. The lighting ratio compares the lit side of a face with the shadow side: 2:1 (one stop) feels open and bright, 8:1 (three stops) moody.

Read how it works: How does film lighting work? · The history of film lighting · More boxes on Glassbox

Chapters in this interactive model

1. Key, fill and back light: Three lamps, one face. Drag them round and read the ratio.
2. Hard light, soft light: Why a big source makes soft shadows, and why light fades so fast with distance.
3. The colour of light: Tungsten, daylight, white balance and the gels that make them match.
4. Light sets the mood: Noir, sitcom, horror, golden hour and moonlight, from the same five lamps.
5. Shaping and controlling light: Barn doors, flags, nets and negative fill. Tungsten, HMI and LED. The gaffer and the grip.
6. Light a dinner scene yourself: Three actors, four lamps, one mood. Can every face still be seen?