Semi-Direct Lighting Design
Semi-Direct Lighting is the kind of lighting provided from a source without reflection from other surfaces.
In daylighting, this means that the light has travelled on a straight path from the sun to the point of interest.
In electrical lighting it usually describes an installation of ceiling mounted or suspended luminaires with mostly downward light distribution characteristics.
Types of Lighting
One of the primary functions of a luminaire is to direct the light to where it is needed. The light distribution produced by luminaires is characterized by the Illuminating Engineering Society as follows:
- Direct Lighting ( 90 to 100 percent of the light is directed downward for maximum use.
- Indirect Lighting( 90 to 100 percent of the light is directed to the ceilings and upper walls and is reflected to all parts of a room.
- Semi-Direct Lighting( 60 to 90 percent of the light is directed downward with the remainder directed upward.
- Semi-indirect Lighting ( 60 to 90 percent of the light is directed upward with the remainder directed downward.
- Highlighting Lighting( the beam projection distance and focusing ability characterize this luminaire)