An IES file, also known as an Illuminating Engineering Society file, is a standardized data file format commonly used in the lighting industry. It contains photometric data that describes the distribution of light emitted by a specific light source.

The purpose of an IES file is to provide accurate information about how light is emitted from a luminaire or light fixture in different directions. This data is crucial for lighting professionals, architects, and designers who need to analyze and simulate the lighting characteristics of various light sources within a specific environment.

The IES file format includes detailed measurements of light intensity and angular distribution, typically represented as a three-dimensional intensity distribution curve known as the photometric “candlepower distribution.” This curve illustrates how the light is emitted in terms of intensity and direction, allowing designers to understand how the light will be distributed in a given space.

IES files are created using specialized software and measurement equipment, such as goniophotometers, which capture data by measuring light at various angles. These measurements are then exported as an IES file, which can be imported into lighting design software or rendering programs to visualize and analyze the lighting effects in a virtual environment.

• Lighting Layout Design

Lighting professionals can import IES files into lighting design software to create accurate lighting layouts for architectural spaces. By placing virtual light fixtures with their corresponding IES files in a 3D model of the environment, designers can analyze the light distribution and make adjustments to ensure optimal lighting coverage and uniformity.

• Energy Analysis

IES files provide detailed data on the light output and distribution of a specific light source. Lighting professionals can use this information to conduct energy analysis, determining the energy consumption and efficiency of a lighting design based on the IES files of the fixtures used. This allows them to optimize the design to meet energy codes and standards while maintaining the desired lighting quality.

There are several lighting design software options available that support the import of IES files. Here are a few popular ones:

• DIALux

DIALux is a widely used lighting design software that allows users to import and work with IES files. It offers a range of features for lighting calculation, visualization, and analysis, making it suitable for both indoor and outdoor lighting design projects.

• AGi32

AGi32 is another powerful lighting design and calculation software that supports the import of IES files. It provides comprehensive tools for designing, analyzing, and optimizing lighting systems in various architectural environments.

• Relux

Relux is a user-friendly lighting design software that supports IES file import. It offers a range of features for indoor and outdoor lighting design, including calculation tools, rendering capabilities, and the ability to generate detailed lighting reports.

IES files are created through a process that involves specialized equipment and software. Here’s an overview of how IES files are typically generated:

1. Measurement Equipment: The first step in creating an IES file is to gather accurate photometric data of a light source. This is done using measurement equipment such as a goniophotometer. A goniophotometer is a device specifically designed to measure and record the intensity and angular distribution of light emitted by a source at various angles.
2. Photometric Measurements: The light source, such as a luminaire or light fixture, is placed on the goniophotometer, which rotates it in different directions while measuring the light output. The goniophotometer captures the light intensity values at multiple angles, creating a comprehensive dataset.
3. Data Processing: Once the measurements are completed, the collected data needs to be processed and organized into a standardized format. This involves converting the angular measurements and intensity values into a specific coordinate system and formatting them according to the IES file standard.
4. IES File Creation Software: Specialized software is used to compile the processed data into an IES file. There are several software options available that facilitate the creation of IES files, including: