Thanks a lot for your response!
Here two screenshots of the test I did on a scene I took from the market place.
On the left, it is from the non-physical lighting values, and on the right, it is the physical lighting values.
**‘non-physical’ method settings: **
Dir intensity : 4 lux
sky light intensity : 1
HDR texture (captured by the sky light) : brightness of 1
I set a fixed exposure that looks good to me for the interior of the train.
Exposure : Set to Auto Exposure Basic
Min brightness : 0.2
Max brightness : 0.2
’physical’ method settings:
Dir intensity : 128 000 lux
sky light intensity : 1
HDR texture (captured by the sky light) : texture multiplied by 25000 (to have a luminance around 5000 cd/m2 in the clouds). But other than the brightness, the texture is the same.
Exposure : Set to manual
Camera settings :
Shutter speed : 100
ISO : 100
Aperture : 6.8
Everything else is the same (lightmass settings etc…).
The exterior lighting looks the same also on the two methods and both contributions of the sky and the sun look the same. Other than the emissive that don’t work with the physical values (I guess I have to increase a lot the emissive’s values), I see some other differences. In general, physical values give more accuracy and realism I think…
But I agree that the overall brightness of the character doesn’t change drastically… So going with the physical values in my project won’t really solve my problem of having dark characters… I will need to cheat on that.