C435 Flashcards
It is a form of energy known as electromagnetic radiation and travels as an electromagnetic wave.
Light
It is the energy radiated in the form of a wave caused by an electric fields interacting with a magnetic field.
Electromagnetic Radiation
Measured as the distance from one peak of one wave to the next wave.
Wavelength
Number of wave cycles per second.
Frequency
It is part of the electromagnetic radiation spectrum that is capable of exciting the retina and ultimately producing a visual sensation. It is the wavelengths of electromagnetic radiation to which the human eye is sensitive.
Visible Light
The amount of light incident on (striking) a surface.
Illuminance
How bright an object appears.
Luminance
It is the ratio of reflected light versus the light striking the surface.
Reflectance
The ratio of light transmitted through body to light illuminating surface.
Transmittance
The ratio of the light absorbed versus the light striking the surface.
Absorptance
The ability to distinguish and interpret different wavelengths of visible light.
Color perception
________ light source emits a fairly even distribution of all wavelengths of light.
Chromatic
___________ light source produces visible light in a very small range of wavelengths.
Monochromatic
A light source that produces a blend of wavelengths evenly distributed across the light spectrum is perceived as ___________.
white light
It is the ability to distinguish fine details. The “keenness” of vision that is necessary to perform tasks such as reading, writing, drafting, sewing, or surgery.
Visual acuity
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
A complete lighting unit which consists of lamps, lamp sockets, any lenses, refractors, or louvers, any ballasts, and the housing.
Luminaire
A luminaire that does not have lamps.
Light fixture
The measure of the perceived power of light expressed in lumens (lm).
Luminous flux
Defined as the quantity of light given out through a steradian by a source of one candela of intensity radiating equally in all directions.
Lumen
The SI unit of luminous intensity, that is, the power emitted by a light source in a particular direction.
Candela (cd)
The ratio of the light output of a light source to the electrical energy consumed to produce the light source.
Luminous efficacy
The color of light emitted by a light source correlates to the temperature of the emitting source.
Correlated Color Temperature
