You
can use IES light profiles to modify light sources to mimic real-world
lights.
The profiles are generally used for interior and architectural scenes where the light is
cast and readily seen on nearby objects like walls, ceilings, and
floors.
Specifications from the Illuminating Engineering Society (IES) define the standards for describing light profiles in the form of
.ies files. Lighting manufacturers provide
.ies files that define the unique way in which each product emits light; for example, how it casts light rays and shadows.