How does VrayIes power perameter interpret Lumens per Square Foot?

[burtonr]

I am trying to accurately simulate a lighting scenario and i have a set of ies files and fixture models from the manufacturer. I just wanted verify that the value given to me in VrayIES's power parameter is accurate to the lighting manufacturer's Lms/ft.

Are system units involved here? Do i need to convert this number if the max scene is in meters?

Of course i realize exposure and ambient light need to be taken into consideration but i want to make sure i am accurately using the specs.

[vlado]

The system units do matter since distances (and from there the light intensity) are based on them.

Best regards,
Vlado

[Deflaminis]

Is there a particular unit that vray likes best? Meters?

[Morne]

Is there a particular unit that vray likes best? Meters?

I'de also like to know this. On large scenes, max behaves better if I switch my units from mm to m. I get a whole lot LESS artifacts in the viewport for some reason.
From past experience however working with biped in character studio, it was a nightmare if you switch units mid project or even try and import something from a file with different units

[Deflaminis]

Yup, nightmare if you do that. However you can point cache the bip model and then apply that in your scene and scale up as needed.