Light Basics
This type of radiant energy is capable of exciting the retina and producing a visual sensation.
What is light?
This metric, abbreviated as CCT, measures the warmth or coolness of a light source's appearance.
What is Correlated Color Temperature?
This unit measures luminous flux and is abbreviated as lm.
what is Lumen?
These are the three primary layers of light in design.
What are ambient, task, and accent?
This type of sensor detects movement based on body heat and requires line of sight.
What is a passive infrared (PIR) sensor?
The visible portion of the electromagnetic spectrum extends from about this range in nanometers.
What is 380 to 770 nm?
This index, abbreviated as CRI, measures how well a light source renders colors compared to a reference source.
What is Color Rendering Index?
This metric expresses light directionally reflected from or transmitted through a surface to the viewer.
What is luminance?
This type of lighting is uniform, spatially oriented, and provides medium-to-low illuminance.
What is ambient lighting?
This control strategy automatically adjusts electric lighting based on available daylight.
What is daylight harvesting?
This organization is responsible for developing many lighting standards and is abbreviated as IES.
What is Illuminating Engineering Society?
These are the three types of photoreceptors in the human eye responsible for color vision.
What are cones?
This instrument is used to measure illuminance in the field.
What is an illuminance meter?
This sustainability rating system for buildings is one of the best known in North America.
What is LEED?
In this mode, lights turn on manually but turn off automatically when no occupancy is detected.
What is vacancy mode?
This term refers to the brightening of the night sky due to scattered artificial light.
What is skyglow?
This technical memorandum, TM-___, provides a more comprehensive method for evaluating light source color rendition.
What is IES TM-30?
This factor, abbreviated as LLF, accounts for various depreciation factors in lighting calculations.
What is Light Loss Factor?
These five principles guide sustainable exterior lighting design to reduce light pollution.
What are the five principles of responsible outdoor lighting?
This type of sensor emits inaudible sound waves to detect motion and does not require line of sight.
What is an ultrasonic sensor?
These are the four components of vision.
What are source, reflecting surface (modifier), receiver (eye), and interpreter (brain)?
This phenomenon occurs when the difference in brightness between objects is heightened when they are placed next to each other.
What is simultaneous contrast?
This law states that illuminance at a point varies inversely with the square of the distance to the target.
What is the inverse square law?
This term refers to the process of evaluating a completed project's performance and user satisfaction.
What is post-occupancy evaluation?
This emerging technology allows for independent control of color temperature and light output.
What is tunable white lighting?