IES lights headache ...

[MovieBear]

Quick question : could it be that the lamp lumen information in an IES file is not used in Corona renderer?
Or am I missing something?
When I create a corona light, specify and activate the IES file, that should normally give me the accurate representation of that lamp, right?  Or do I manually have to set the intensity?

[TomG]

AFAIK, the IES file does not contain an absolute intensity for the light (which is what enables you to still adjust it as needed for your scene using the light settings themselves) but instead contains just the distribution of intensities. IES is an extensible format (I am told) so it is possible that some IES files may contain an absolute intensity, but in those cases we wouldn't be reading or using that, just the map of how the light's intensity should be distributed (which is what gives the patterns of light and dark in the IES light).