Footcandles are the most common unit of measure used by lighting professionals to calculate light levels in businesses and outdoor spaces. A footcandle is designed as the illuminance on a one square foot surface from a uniform source of light. The Illuminating Engineering Society (IES) recommends footcandle levels to ensure both safety and adequate lighting for specific tasks.
This IES Footcandle Guide is an interpretation and abbreviated guide to the IES Footcandle Handbook, 10th edition.