The color of light Flashcards
It is the ability to DISTINGUISH and INTERPRET different wavelengths of visible light.
Color perception
An object that absorbs all of the longer wavelengths and reflects the shorter wavelengths will be perceived as ________ or _________.
violet , blue
A light source producing a BLEND of wavelengths that are evenly distributed across the light spectrum is percieved by the human eye as __________ or ____________.
white, normal light
When they are combined togetherm primary colors of light produce ________.
white
The colors of pigment are __________, _________ and _________ and are opposite of the colors of light
magenta, cyan, yellow
A _________ light source emits a fairly EVEN DISTRIBUTION of all wavelengths of light. Most light sources are not fully __________.
chromatic x2
A _________ light source produces visible light in a very small range of wavelengths;
monochromatic
The type of wavelengths emitted by a light source will influence _________.
color
A light source that produces a blend of wavelengths evenly distributed across the light spectrum is perceived as _______________.
white light
What are the two methods are used to rate the QUALITY OF COLOR emitted by a light source.
Color Temperature, Color Rendering Index
It is the ability to distinguish fine details. It is the ____________ of vision that is necessary to perfrom tasks such as reading, etc.
Visual acuity, keenness
It is a device that generates light
lamp
This kind of lamps provide light source by INCANDESCENCE, which is the emission of light caused by heating the filament.
incandescent lampS
Gaseous discharge lamps can be divided into 2 or more subcategory such as:
low-pressure lamps, high-intensity discharge
Low-pressure lamps examples
fluorescent lamps
-low pressure sodium lamps
High intensity discharge lamps
mercury vapor lamps
metal halide lamps
high pressure sodium lamps
It is a COMPLETE LIGHTING UNIT which consists of lamps, lamp sockets, any lenses, refractors or louvers, any ballasts and the housing.
luminaire
A __________ is a luminaire that does not have lamps.
light fixtureS
The term ________ is generally used to describe a luminaire.
lantern
The term ________ is generally used to describe a luminaire.
lantern
It is the measure of the perceived power of light expressed in LUMENS.
Luminous flux
A __________ is defined as the QUANTITY of light given out through a STERADIAN by a source of one ________ of intensity radiating equally in all directions.
lumen, candela
___________ is the SI unit of luminous INTENSITY — that is the power emitted by a light source in a particular direction.
Candela
It is the ratio of the light output of a light source to the electrical energy consumed to produce the light source. It is expressed in _________.
Light efficacy, LPW
The color of light emitted by a light source correlates to the _____________ of the emitting source. A _______ body is a theoritcally ideal body thet perfectly radiates energy.
temperature, black
Technically, color temperature only applies directly to light sources that _________. Gaseous discahrege lamps is rated by their _______ or ________ color temperature
incandesce ( emit light from heating), correlated, apparent
It is the method of numerically comparing the color distribution of a light source to a reference lamp.
In theory, a lamp with a ________ CRI more closelt emulates the reference lamp and provides a better color rendition.
color rendering index (CRI)
higher
A ________________ curve is a graphic presentation of the quantities of light emmited by a lamp by wavelength component. These curves are a plot or _______ power versus specific ________ across the light spectrum.
They provide a visual ________ of the color characteristics of the light emittted by the source over the visible part of the spectrum.
spectral power distribution
radiant
wavelength
fingerprint
It is the rated life of a lamp in its median life expectancy, expressed in hours. It is the cumulative time that lapses before ___% of a representative group of lamps have failed and the other lamps in the group continue operating.
lamp life, 50
As lamps operate, the ___________ will decrease. As incandescent lamps operate their light output degrade to about ____% of lamp’s initial lumen output.
Fluorescent degradation - ____ to ___%
HID degradation - ____ to ___%
luminous flux
85
60 , 80
50 70
