What I don't understand however, how does this game looks perfectly for me natively (nVidia card)? They added a built-in patch in the driver? Or, the engine selects the intensity value depending on hw vendor value and various driver cap bits? (My HL2 version is probably a fixed version and that's …

I believe it was always like that in retail release of HL2 (IDK about Sin Episodes) because there are reports of this issues that date back to november of 2004 the flashlight and fog issue, there could be a possibility that sin episodes uses the 2004 old source, I will maybe check the 2006 rerelease …