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Join
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Information
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Sponsorship
IES Progress Report
Featured Events
Light + Justice Symposium
IES24 Conference
Street & Area Lighting Conference
Research Symposium
Special Events
Light for Life Virtual Symposium
Illumination Awards & Gala
Lighting Education Tour
Aviation Lighting Conference
Research & Education
Research
About IES Research
Publications
FIRES Forum
Past Projects
IES Lighting Ready Reference App
Education
eLearning Portal
Upcoming Webinars
Request IES CEU/AIA-LUs
LC Study Group
Register Now for Our Next Webinar
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Nomenclature & Definitions
Standards Errata & Addenda
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IES Standards Toolbox
My Lighting Library
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speed of light
[3.13] (See
Spectral Parameters
.)
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