IES (Illuminating Engineering Society) photometric files are the standard data format that describes how light is distributed from a light fixture, and they are an essential tool for professional lighting design and code compliance.

1. What Data Is Included in an IES File? IES files contain precise measurements of light intensity at every angle from the fixture, total lumen output, candela values, light distribution pattern (Type I to Type V for outdoor lights), and mounting height recommendations.

2. How Are IES Files Used? Lighting designers import IES files directly into software like DIALux, Relux, or AGi32 to create accurate lighting layouts, calculate average and point-by-point illuminance levels, check uniformity ratios, and ensure designs meet local building code requirements before installation.

3. Why This Matters for Buyers: Without accurate IES files, you cannot verify that a fixture will deliver the light levels promised by the manufacturer, leading to over-lighting (wasting money on extra fixtures) or under-lighting (failing code inspections and creating unsafe spaces).

4. Our IES File Policy: We provide free, third-party tested IES files for every one of our standard products, available for immediate download on each product page, with custom IES files available for modified or custom fixtures within 3 business days.