Image courtesy of Mihai Illuta. Ajax model courtesy of Jotero
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Both formats contain the luminous intensity at any angle, measured in laboratory using light sensors located all over a spherical dome around the light source, pointing to the center of the dome so that the data capture method considers all lamps as point sources.
You can use IES/EULUMDAT emitters with any type of geometry but for the most predictable results it is recommended you apply it to a small sphere (a few centimeters in radius). The While the Emission color settings work here identical than on regular Area emitters, the intensity of the.IES/.EULUMDAT light itself is already specified in the file - , so normally you shouldn't need to change it for realistic results. But you can adjust the intensity if you wish using the Intensity parameter which acts as a multiplier for the built-in intensity of the .IES/EULUMDAT file. You can also change the intensity using Multilight, but keep in mind that Color Multilight is not compatible with this type of emitter.
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