hello Franck,
I searched a bit because Iray accepts IES type measured light files. I found where it is necessary to import this file, look in the “shaping” part of the properties of the light and test to see. I did not quite understand everything but we will see later.
I created a topic on the IES files we’ll see if there are people with more ideas.
bye bye
IES file with light - Apps / Create - NVIDIA Developer Forums