IES File Documentation

Overview

Feature Value
File Format Name IES Photometric Data File
Extension .ies
MIME Type text/plain
Format Type Text
Primary Use Describing the distribution of light
Standardization IESNA (Illuminating Engineering Society of North America)
Introduction Year 1986
Character Encoding ASCII
Keyword/Identifier Lines Starts with 'IESNA', 'IES' or similar
Data Sections TILT, Lamp, Ballast, Photometric, Geometry etc.
Photometric Web File Support for web distribution
Application Lighting simulation and analysis
Supporting Software DIALux, Relux, Photopia, LightTools etc.
Measurement Units Candelas, Lumens, Degrees
Data Format Numerical, delimited by spaces or newline
Photometric Type Type A, Type B, Type C photometry
Versioning IES LM-63-1986, LM-63-1991, LM-63-2002, LM-63-2019 etc.
Editable With text editors
Compression Typically uncompressed, though compressible
Popularity Widely used in architectural and theatrical lighting design