Modelling indicators for combined side and overhead lighting systems

Abstract

For an observer the normal direction of viewing of the other occupants of a space is commonly at 90° to the downward vertical and may vary in azimuth over 360°. The light flow from overhead lighting installations intersects this plane of viewing at 90° whereas that from side lighting is parallel to the plane of viewing. A system of modelling indicators is introduced which takes into account these relationships and is offered as a means of studying combined artificial and daylight lighting systems. The point is made that a specification system for modelling simple enough for practical use cannot be completely comprehensive and give a guaranteed appearance. For this reason the concept of the modelling indicator is introduced and stipulated to give an indication of the type and variety of modelling to be expected.