It is defined as “visually evaluated radiant energy”
Light
Based on ____ All heated bodies emit energetic corpuscles, each having the same very high velocity and a size dependent upon its color
Newton (1600’s)
Based on _____ Every point on an advancing wavefront serves as a source of secondary wavelets, sent out radially
Huygens (1670)
Basend on _____ , it Showed that all radiant
energy consists of electromagnetic waves travelling at
the velocity of light.
Maxwell & Hertz (19th century)
Best natural source of light is?
Sun
The visible portion of the electromagnetic spectrum includes all wavelengths is between?
380 nm and 770 nm
It tend to produce light with greater amounts of power in the longer wavelength ends of the spectrum
(reds & oranges);
Incandescent
basis for the development of all manufactured paints and dyes
Subtractive primaries
what the eye uses in the process of seeing light and color
Additive primaries
Factors that can be controlled in the design of a lighting system
- Direction
- Color
- Brightness (luminance)
- Quantity (illuminance)
A Single point source of light and Provides highlights and casts shadows providing contrast and producing definite focus
Key Lights
Multi-directional or diffuse light and Reduces shadows on an object caused by the key light
Fill lighting
It Occurs when light strikes a surface at a sharp angle, nearly parallel to a rough surface
Grazing
Occurs when light strikes a surface at a wide angle
Wall Washing
A Light source is used not to illuminate an object itself, but its background
Silhouette
Produces shadows that are reversed from how an object is shadowed in daylight
Creates an eerie, unnatural effect because it replaces the more familiar overhead orientation of the light source
Uplight
CCT means
Correlated Color Temperature
CRI means
Color Rendering Index
Acceptable range of CCTs for
indoor environments is
between?
2500°K and 5000°K
It rating indicates how well an object’s colors are rendered by a source.
CRI
Quantity is described in?
Illuminance
result of excessive, uncontrolled light within the field of view
Glare
Defined as the flow of light, Φ. Measured in?
Luminous Flux, Lumens
Average illumination of a surface is
luminous flux per unit area.
Illuminance
