ANSI/IES LS-1-22, Lighting Science: Nomenclature and Definitions for Illuminating Engineering
The IES defines illumination engineering terms in ANSI/IES LS-1-22, is available here online. You can search terms by their first letter using the categories listed in the Categories window, by the first letter of the term in the alphabetical list below, or by typing the term in the search window. You can find the Introduction material for LS-1-22 on these pages:
- Copyright, Disclaimer, and American National Standards Statement
- Foreword, Nomenclature Committee members, Introduction, and Scope
- Spectral Parameters Used in Illumination Engineering
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- reflex reflector
- refraction
- refractor
- regions of the electromagnetic spectrum
- regressed
- regular (specular) reflectance
- regular (specular) reflection
- regulation (of voltage)
- relative contrast sensitivity, RCS
- relative luminosity
- relative luminosity factor
- remote control switch
- resolving power
- resultant color shift
- retina
- retinal burn
- retinal burn hazard function
- retinal ganglion cells
- retinal hazard region
- retro-reflector (reflex reflector)
- RGB color system
- rheostat
- rhythmic light
- ribbon filament lamp
- Risk Group 1 (low risk)
- Risk Group 2 (moderate risk)
- Risk Group 3 (high risk)
- risk group classification (of lamps)
- rods
- room cavity
- room cavity ratio, RCR
- room coefficient,* Kr
- room index*
- room ratio*
- room surface dirt depreciation, RSDD
- room utilization factor (utilance)
- roundel
- runway alignment indicator
- runway centerline lights
- runway edge lights
- runway-end identification lights
- runway exit lights
- runway lights
- runway threshold
- runway visibility
- runway visual range, RVR
- Sample Color Fidelity (Rf,CESi)
- saturation of a perceived color
- scene master
- scenic projector
- schedule (television, film, theater)
- scoop
- scotopic vision
- scrim
- scroller
- sealed-beam headlamp
- sealed-beam lamp
- sealed-beam spotlight
- searchlight
- seasoning
- seasoning time
- secondary standard
- self-ballasted lamps
- self-luminous exit sign
- semi-direct lighting
- semi-indirect lighting
- senior (television, film, theater)
- service period
- set light
- shade
- shade (daylighting)
- shading coefficient
- shielding angle (of a luminaire)
- short-arc (compact-arc) lamp
- shutters
- SI unit of luminance
- side-back light
- side light
- side marker lamps
- signal shutter
- signaling light
- signaling system
- silicon controlled rectifier, SCR
- size threshold
- sky glow
- sky light
- sky luminance distribution function
- skylight
- snoot
- soft light
- solar constant
- solar efficacy
- solar illuminance constant
- solarium
- solid angle
- solid angle factor, Q
- spacing (roadway)
- spacing-to-mounting-height ratio, S/MH
- spatial daylight autonomy (sDA)
- special color rendering index