Language of Light Flashcards
Quantity of Light
How much light is produced by a light source
Luminou Flux ( Light Output)
is the light produced by a lamp expressed in Lumens (lms)
Illuminance (E) is ?
light that arrives at a 1sq ft or 1 sq m surface or task plane expressed in footcandles or lux.
Illuminance is not perceived by the eye. The eye sees ______ light.
reflected
Luminance is _________ Perception
Brightness
What does Reflection and Transmission of light mean?
How light is reflected or transmitted respective of different materials and the surface characteristics (how light reflects off of anything)
No Transmission happens with what materials?
Opaque materials block light transmission and cast shadow
Diffused Transmission happens with what materials?
Translucent Materials (frosted glass)
Transmission happens with what materials?
Light transmitted through transparent material (clear glass or plastics)
Specular Reflection
Light is reflected from an opaque and shiny surface in a pattern where the angle of incidence (arriving is equal to te angle of exitance (reflectance) . ANGLE OF ARRIVAL IS THE SAME AS EXITANCE
Diffuse Reflection
Light is reflected in multiple directions, where the surface is matte.
Luminance (L)
is reflected light
Luminance is measured in _____.
candelas/m [cd/m]
The perceptual sensation of Luminance is ____________ __________ (BP)
Brightness perception
Brightness if not controlled properly will produce ___.
Glare
Direct Glare:
is generated from an improperly shielded light source (light coming directly from source!!!)
Indirect Glare:
Light that is reflected off a shiny or glossy surface (Light coming off something else!!!)
Disability Glare:
Light that causes severe discomfort or even temporary blindess. (glare that makes you BLIND)
The colour appearance of light is the ____________ Colour of a light source
spectral
Colour Appearance of a light source describes its apparent warmness or coolness expressed in the degree _____.
Kalvin (k)
Color Temperature (CT) or CHROMATICITY
refers to the presence and proportional relationship of light waves in a light source and are illustrated on charts called Spectral Power Distribution (SPD)
Color Rendering and Color Rendering Index (CRI)
how light source will affect the appearance of a surface colour
Subjective Impression with warm light
Suggests that warmer light appearance is desirable for low luminance, non uniform atmospheres, INC. 2600K-3100K.
Subjective Impression with cool light
FL. 2700-3100K and higher yet at 4100 K is more desirable for higher illuminance levels and uniform atmospheres.
Perceived Colour has been correlated to a ______ _______ Factor.
” Luminance Reflectance Factor” (LRF”
The attributes of colour play a role in determining the percentage of __________ reflectance.
Light reflectance.
