Everything you need to know about IES file
by Penglight | Date: 3rd Sep, 2023
In the world of architectural lighting design and engineering, achieving the perfect balance between aesthetics, functionality, and energy efficiency is a paramount goal. Lighting professionals and designers strive to create captivating and well-lit spaces that enhance the visual experience while meeting the technical requirements of the project. To accomplish this, one tool stands out as a critical element in accurately representing how light will interact within a specific space. This tool is known as the IES file.
The Illuminating Engineering Society (IES) file, often referred to as an IES file, is a standardized data format that holds the key to understanding the intricate characteristics of light emitted by a specific light source. It contains essential photometric information that helps professionals analyze, simulate, and fine-tune the lighting effects within architectural spaces.
Let’s delve into the fascinating world of IES files and explore how they illuminate our understanding of light and space.
About the IES
Established in New York City on January 10, 1906., the Illuminating Engineering Society (IES), formerly the Illuminating Engineering Society of North America (IESNA), is the recognized technical and educational authority on illumination.
About the IES File
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.
Following are the two most common expressions of IES photometric curve:
Rectangular coordinate representation method
Polar coordinate representation method
How lighting professionals use IES files in architectural design?
- 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.
- Daylighting Analysis
Daylighting is the practice of utilizing natural light to illuminate indoor spaces effectively. By combining IES files of artificial light sources with daylight simulation software, lighting professionals can assess the interaction between artificial and natural light. They can analyze how the IES-file-based light fixtures will complement or supplement daylight, ensuring a balanced and energy-efficient lighting design that harmonizes with natural lighting conditions.
- Renderings and Visualizations
IES files are often used in rendering and visualization software to create realistic lighting simulations. By applying IES files to virtual light sources, lighting professionals can accurately represent the lighting effects and ambiance of a space. This helps architects, clients, and stakeholders visualize how different fixtures and lighting schemes will influence the overall appearance and mood of the architectural design.
- Compliance and Documentation
IES files provide standardized photometric data, which is essential for compliance with lighting regulations and documentation requirements. Lighting professionals can use IES files to demonstrate that a lighting design meets specific criteria, such as illuminance levels, uniformity ratios, glare control, and light trespass restrictions. These files serve as a means of verifying and communicating compliance with industry standards and building codes.
Overall, these are just a few examples of how lighting professionals use IES files in architectural design. The versatility and accuracy of IES files enable designers to make informed decisions, optimize lighting performance, and create visually appealing and energy-efficient lighting designs for various architectural applications. If you do not have engineers to help you with the IES files, Penglight can analyze the IES files for you.
Detailed explanation of IES file data
Let’s explain further about the index area.
This refers to the number of light sources, usually represented by 1, as the LED light is illuminated as a whole set.
This refers to the luminous flux of the light fixture.
Here are the quantities of vertical angles and horizontal angles.
This is a unit of measurement, generally expressed in imperial (feet) and international (meters).
This is the size of the luminous surface, in the order of width, length, and height. After modification, changes will appear on the model in the simulation software.
This figure refers to the input wattage.
What lighting design softwares support importing IES files?
There are several lighting design software options available that support the import of IES files. Here are a few popular ones:
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 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 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.
- Visual Lighting Software
Visual Lighting Software is a versatile lighting design and analysis software that supports the import of IES files. It offers a wide range of tools for designing, simulating, and evaluating lighting schemes, making it suitable for various architectural applications.
- Autodesk Revit
Revit is a popular BIM (Building Information Modeling) software that also supports the import of IES files. While it is primarily used for architectural design, it includes lighting design capabilities, allowing users to import IES files and analyze lighting within the context of their architectural models.
How IES files are created and what software is commonly used?
IES files are created through a process that involves specialized equipment and software. Here’s an overview of how IES files are typically generated:
- 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.
- 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.
- 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.
- 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:
- Goniophotometer Software: Some goniophotometers have built-in software that enables users to directly export the collected data as an IES file.
- Photometric Data Analysis Software: Dedicated software tools are available that allow users to import the measured data and generate IES files. These software options provide additional features for visualizing, analyzing, and manipulating the photometric data before exporting it as an IES file.
- Lighting Design Software: Many lighting design software packages include functionality for creating IES files. These software solutions often integrate with goniophotometers or allow users to import measured data, which can then be converted into IES files.
Commonly used software for creating IES files includes Photometric Toolbox, Photopia, and LightPro.
Note: You do not need to make IES files yourself, lighting manufacturers can provide IES files for their products, which are created in-house and made available for download.