In the realm of lighting design, you may encounter IES files. These text files contain numerical data representing the three-dimensional "shape" of a light fixture’s projection. Closely related to "beam spread," or "beam angle," an IES file captures the nuanced light output pattern emitted by a particular fixture. We'll shed some light on how manufacturers capture this photometric data, and how designers use it.
Visit our Lighting Features page for even more lighting design tools.
Special thanks to Puneet Sharma for the goniophotometer footage.