This page describes the use of V-Ray photometric lights.
Overview
Visualizing IES Profiles
The properties of an IES file can be visualized with Photometric Viewer software, which you can easily find online. Visually, the IES profile uses a graphed curve to show the shape and intensity of the light's emission. Depending on the software used, you might also be able to render a grayscale representation of how the light will look in a scene. Using a Photometric Viewer will help you better understand how the IES files you are using will affect your scene's lighting.
The graph below shows the IES profile of a typical bollard or post light, a type of light commonly used in architectural outdoor scenes. The rendered thumbnail is shown as an inset.
General
Intensity and color
IES override
Options
Sampling
Decay
Viewport
Examples
Example: Shape
This example shows how light is affected by the different shapes of the IES Light. Circle and Sphere shapes examples are also compared with different diameters - 1.0 and 10.0.
Circle, Diameter = 1.0
Circle, Diameter = 10.0
Default shape From the IES light
Point
Sphere, Diameter = 1.0
Sphere, Diameter = 10.0
Example: Near Decay Start
This example shows the variances achieved by changing the Near decay start parameters only.
Near decay start 10, Near decay end 60
Near decay start 30, Near decay end 60
Near decay start 50, Near decay end 60
Example: Near Decay End
This example shows the variances achieved by changing the Near decay end parameters only.
Near decay start 0, Near decay end 10
Near decay start 0, Near decay end 30
Near decay start 0, Near decay end 50
Example: Far Decay Start
This example shows the variances achieved by changing the Far decay start parameters only.
Far decay start 10, Far decay end 60
Far decay start 30, Far decay end 60
Far decay start 50, Far decay end 60
Example: Far Decay End
This example shows the variances achieved by changing the Far decay end parameters only.
Far decay start 60, Far decay end 60
Far decay start 60, Far decay end 100
Far decay start 60, Far decay end 120
Example: Near and Far Decay
This example shows some artistic lighting results achieved by using both Near and Far decay options.
Near decay start 0, Near decay end 15, Far decay start 30, Far decay end 60
Near decay start 20, Near decay end 35, Far decay start 40, Far decay end 55
Near decay start 30, Near decay end 60, Far decay start 90, Far decay end 120