Realistic Light Source

Thank you sir,

In general my problem is a little more complex.

I’ve already created an Sphere actor with the mentioned material, created the variable aswell. My problem is with it being realistic. By realistic I mean accurate compared to real life light source.

What I need is a formula for the material itself so I can change the intensity by giving candela values.
I found one: CandelaVariable / (4 * Pi * RadiusOfLightSourceSphere²)" and then multiply by color to the emissible input in the material.

It works but how accurate is it? When i set up for example spot light in details i can change intensity in candelas and that’s exactly what i want to achieve with my material, just not sure how possible it is.

Z