What does Gels mean?
Gels are thin, flexible sheets of colored or diffusion material placed in front of lighting instruments to modify the quality, color, or intensity of the light they produce. Color gels change the color temperature or hue of a light source — for example, adding a warm amber gel to simulate late afternoon sunlight or a blue gel to suggest cool artificial light. Diffusion gels soften the quality of a light, reducing harsh shadows and creating a more flattering or natural light quality. Gels are a fundamental tool in both film and theater lighting and are used in virtually every professional production.
Example:The gaffer placed a CTO (color temperature orange) gel on the key light to warm up the color temperature and match the quality of the afternoon sunlight coming through the practical window — ensuring the artificial light blended seamlessly with the natural light in the scene.
Example: The lighting designer for the theater production used deep blue gels on the back lights to create a cool moonlight effect for the outdoor night scene, contrasting with the warm amber gels on the practical lantern props to suggest the character’s firelight.
Did you know?
The major manufacturer of professional lighting gels — Rosco — produces hundreds of different colors and diffusion materials, each identified by a specific number that has become industry shorthand. Cinematographers and lighting designers communicate using these numbers — ‘Give me a 216 on that back light’ or ‘Put a full CTO on the key’ — as a precise shared vocabulary for describing exactly what light modification is needed. Learning this vocabulary is part of the practical language of the professional lighting world.
You can also find “Gels” and related terms in this category: Filming and Production.
