The following are some of the various ways that artificial light is dispersed:
Diffuse up lighting
Concentrated up lighting
Diffuse down lighting
Concentrated down lighting
Multidirectional lighting
Semi-direct lighting
Semi-indirect lighting
Diffuse up lighting
Purpose: To achieve uniform ambient lighting in a space. Light is reflected off the ceiling to introduce it indirectly into the space.
Property: Beam spreads from 80° to 120° upwards. Even illumination in the space.
Diffuse uplightingconcept
Concentrated up lighting
Purpose: Create areas of high luminance on the ceiling with dark areas in between.
Property: Beam spreads from 30° or lower upwards.
Concentrated up lighting concept
Diffuse down lighting
Purpose: To achieve uniform ambient lighting in a space. To illuminate the horizontal surface below the luminaire.
Property: Beam spreads from 80° to 120° downwards.
Diffuse down lighting concept
Concentrated down lighting
Purpose: Create areas of high luminance on the floor with dark areas in between.
Property: Beam spreads from 30° or lower downwards.
Concentrated down lighting concept
Multidirectional lighting
Purpose: To create a stimulating, high brightness interior.
Property: Light emitted in several directions.
Multidirectional lighting concept
Semi-direct lighting
Purpose: Light emitted in only upward and downward direction. 60% to 90% of light is downwards.
Property: Moderate contrast in the space.
Semi-direct lighting concept
Semi-indirect lighting
Purpose: Light emitted in only upward and downward direction. 60% to 90% of light is upwards.
Property: Moderate contrast in the space.
Semi-indirect lighting concept
Factors That Affect Light Distribution
The following are a few factors that affect the distribution of light:
Illuminance
Illuminance is the amount of light falling on a surface.
Luminance
Luminance is the amount of reflection, from a surface, of light.
Contrast
Contrast is the relationship of an object's background to its brightness.
Reflectance
Reflectance is the ratio of light falling on a surface to the light reflected from a surface.
Categories of Lighting Affects
The following are a few categories of lighting affects:
Wall Washing
Wall Grazing
Slot Lighting
Accent lighting
Cove lighting
Wall Washing
Purpose: To achieve even illumination on a vertical surface, side to side and top to bottom. The luminaire is placed at one-quarter of the distance away from the surface. Spacing between luminaires varies from one-quarter to one-half of the wall height depending on the luminaire.
Property: Even illumination on a vertical surface.
Use: To highlight a vertical surface, hiding the surface imperfections, and flattening the texture.
Wall washing example
Wall Grazing
Purpose: To reveal the texture of a surface. The luminaire is placed intentionally close to the surface.
Property: Even wall lighting highlighting its texture.
Use: Used to illuminate surfaces with interesting textures such as stone, brick, etc.
Wall Grazing example
Slot Lighting
Purpose: To light a wall accentuating the junction of the wall and the ceiling, indirectly lighting the space.
Property: Brighter illumination at the top of the wall; indirect illumination in the rest of the space.
Use: To accentuate the ceiling plane.
Slot Lighting example
Accent lighting
Purpose: To illuminate an object to focus attention on it. The luminaire is ideally located so that it produces light about 30° from vertical, which is generally agreed best for art.
Property: Even distribution of light on the object
Use: To accentuate an object in space.
Accent lighting example
Cove lighting
Purpose: To directly illuminate the ceiling, and indirectly illuminate a space, accentuating the ceiling plane.