What Are IES Light Files?
IES files—also known as IES photometric files—are standardized text files that contain precise photometric data of a luminaire. Developed by the Illuminating Engineering Society (IES), these files allow software tools to simulate how a specific light fixture behaves in a real environment.
They describe:
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Light distribution patterns
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Beam angles
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Luminous intensity (in candela)
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Fixture orientation
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Lumen output and more
The format is typically .ies and is readable by all major lighting design platforms like DIALux, AGi32, Relux, Revit, and AutoCAD.
Why IES Files Matter in Lighting Projects
In professional lighting design, visualizing light before installation is crucial. IES files allow you to:
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Perform realistic lighting simulations and renderings
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Evaluate illuminance levels (lux/footcandles) on surfaces
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Validate compliance with IESNA recommendations
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Compare different fixture photometry in the same project
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Ensure accurate light distribution for UGR, LPD, and CRI goals
For large-scale projects—hotels, offices, museums, public spaces—IES files are essential for designing with precision and justifying specs during submittals or approvals.
What’s Inside an IES File?
An .ies file may look like raw text, but it contains structured data such as:
How to Use IES Files in Design Software
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Download from the manufacturer (e.g., Faro Barcelona offers IES files for all its luminaires).
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Import into your software (Revit, DIALux, AGi32).
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Place the luminaire in the model and simulate scenes.
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Analyze outputs: lux levels, glare, shadows, distribution on walls/floors.
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Refine your design by comparing fixture options and adjusting placement.
Where to Find Reliable IES Files
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Manufacturer websites (e.g., Faro Barcelona)
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Online photometric libraries
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Lighting spec tools integrated in BIM software
Be sure to only use certified LM-79 tested files to ensure accuracy and code compliance.
