The camera lens attenuation (q). Set this number to 0.78 for lighting to be unitless (1.0cd/m^2 becomes 1.0 at EV100) or 0.65 to match previous versions (1.0cd/m^2 becomes 1.2 at EV100).
Usage
r.EyeAdaptation.LensAttenuation [value]
Set via the console (~) or in DefaultEngine.ini / DefaultGame.ini.
