The IES file is a photometric file typically used to describe the light distribution from any optic, lighting fixture or source. Certain optical simulation packages (e.g. Dialux, Relux, etc.) use IES files to predict expected optical performance. The IES file re-creates the light intensity distribution, so it only contains angular information. It also assumes the light source is a point (i.e. it has no size) and the surface or object you wish to illuminate are in the ‘Far-field’. If you want to model the performance of an additional optic with our Carclo optic then you need the ‘Ray set’ for that particular optic. The Rayset contains positional & angular data (i.e. Near-field data).
