Luminous Dimensions

Refers to the luminous (that is, light emitting) opening of the luminaire, not its physical dimensions. They are meant to approximate the luminous opening (either as a luminous area or luminous volume) for lighting calculations. It is assumed that there is only one luminous opening in each IESNA LM-63-2002 data file. DLC SSL Technical Requirements Version 5.1 luminaires may have more than one luminous opening, and regardless of the number of luminous openings, the width, length and height fields in the .ies file must use one of the luminous shapes available in IES LM-63 to describe the smallest geometry that completely encompasses all of the light emitting surfaces of the product.