I use the following tweaks, they are used in connection with Nightime settings much darker, and Vurt's Weather tweaks as well.
[LightAttenuation]UseConstant=0ConstantValue=http://forums.bethsoft.com/index.php?/topic/1116601-lighting-and-other-ini-tweaks/0.0;UseLinear=1LinearMethod=1LinearValue=0.1LinearRadiusMult=0.618;UseQuadratic=1QuadraticMethod=2QuadraticValue=4.0QuadraticRadiusMult=2.0;OutQuadInLin=0
Well, I actually use a combo of all three lighting methods. Constant, Linear and Quadratic.
But once you use Constant, doesn't it cancel out any Linear/Quadratic settings?
As far as I know, Constant is either On or Off. If you use it, other tweaks are ignored.
Check out http://www.yacoby.net/es/forum/9/6027921165763400.html for a conversation on the topic.