Design Nomenclature / Light & Optics

Practical

Also called practical light, motivating source

A fixture that appears in frame and is actually lit — a lamp, a screen, a candle. It motivates the light the audience is asked to believe in, though it rarely supplies the exposure; that comes from sources outside the frame, matched to the practical's direction and colour.

Plan view: a table lamp inside the camera's drawn field of view, and a second, larger lamp just outside that field on the same side, both throwing onto the subject from the same quarter — the sheet confirming the small one is in frame and reporting each lamp's azimuth off the camera axis.

In practice

The word survives intact in CG, doing the same job: a visible emissive object that justifies the off-camera area light doing the real work.

How this term connects

Area lightKelvinKey lightLow keyWhite balancePractical
Related Confused with