IES Light power problem.

[prv_works]

Is it normal that V-Ray 7 IES lights don’t have watts, lumens, or any other power measurement system?
Another issue is the ridiculously high power value I had to set (400.000,00) just to get even a faint light in this four meter wide cube.
Are there missing features for this type of light, or is this just how the values are handled now?

GPU Optix here..

Thanks.

01.png

[daniel.kapsazov]

prv_works

When it comes to using IES lights, all the specifications of the light are contained within the .ies file.
These types of lights usually come with predefined values for scale, power, shape, etc.

Here is an example comparing V-Ray for Cinema 4D and Blender IES Light with default values:
blender_2025-05-07_19-20-35.png

If you leave the Power value at 0, V-Ray will use the intensity defined within the .ies file.
If you're not seeing any light at that point, it's likely that the file itself needs to be checked.

The Power value is calculated in lumens, so you should typically get a good result in the range of 500–1000 lumens.

You can find more details in our documentation page: https://docs.chaos.com/display/VBLD/IES+Light , and of course, if you have any further questions, I remain available to help.

[prv_works]

daniel.kapsazov


Alright, I'm gonna test this out and check the documentation too. Thanks!