Addendum 3 for ANSI/IES RP-16-17, Nomenclature and Definitions for Illuminating Engineering

If you, as a user of ANSI/IES RP-16-17, believe you have located an error not covered by the following revisions, please e-mail your information to Pat McGillicuddy,, or send a letter to Pat McGillicuddy, Manager of Standards Development, IES, 120 Wall St., 17th Floor, New York, NY 10005.
Additions will be posted as they become available.

Addendum 3 was approved by the IES Standards Committee on February 28, 2019, and by the American National Standards Institute (ANSI) on July 29, 2019.

Click here to download Addendum 3 for RP-16-17, Nomenclature and Definitions for Illuminating Engineering. [PDF 206KB]

New Terms and Definitions:

absolute photometry
artificial sky glow
attenuation coefficient
luminance coefficient, q
natural sky glow
obtrusive light
reduced luminance coefficient, r
relative photometry
sky glow
solid state lighting (SSL)
spectral power distribution (SPD)
spectral transmittance distribution
spill light
total spectral radiant flux

New Controls Terms:

high-end trim
institutional tuning
lighting system
load shedding
lumen maintenance control
networked lighting control system
spectral tuning

Added to Index only:

constant lumen output
lumen depreciation compensation