IES stands for Illuminating Engineering Society. IES standard file format was created for the electronic transfer of photometric lighting data over the web. It has been widely used by many lighting manufacturers and is one of the industry standards in photometric data distribution. An IES file is basically the measurement of distribution of light (intensity) stored in ASCII format. You can think of it as a digital profile of a real world light.
In IRender nXt IES files can be used for creating lights with shapes and physically accurate form. IES Spot Lights can cast light more realistically by accounting for the reflective surfaces in the light fixture, the shape of the light bulb, and any lens effects.
IES light files are created by many major lighting manufacturers and can be downloaded freely from their sites.
IRender nXt also provides 30 standard IES Light profiles which can be used to create many standard lighting shapes.
30 IES Light profiles supplied with IRender nXt
- See: IES Samples
Using these patterns, and selecting a pattern which give the appearance you like can really improve your renderings.
Using IES Lights
The easiest way to use IES Lights is to place a Spot Light from our IRender Ready Light Wizard, and place one of the IES Patterns on it.
Or to place one of the Wall lights from the Wizard which already have IES spotlights in them.
After Placeing a Spit Light or Wall Sconce, you can right click on it to change the IES Pattern.
Using IES Files
IES files (.ies) are photometry files which define the distribution of light from a light source. Luminaire manufacturers often provide these files. By using the IES file to define your distribution, rather than one of the standard, tyical patterns, you can more accurately depict your luminaire. Also, you can use the IES file to define the intensity of your lamp.
The vast majority of IES files are known as Type C goniometry files. These are supported by IRender nXt.
Type A files are occasionally used by the automobile industry to define headlights. Type B files are sometimes used to define floodlighting. Type A and B are not supported in nXt.
IES distributions already include the effects of luminaire elements such as baffles, reflectors, and diffusers. It is important to exclude these elements from the calculation by properly tagging the non-source parts of your luminaire. IES distributions are often asymmetrical, so the process of aiming the source includes not just a light direction, but an orientation direction as well.
Sometimes you would like to see the distribution of an IES light before adding it to your model and rendering it.
We use a program called IES Viewer .
It can examine an IES file for you and show you what the light distribution is.
See: IES Viewer .