1. Run vanilla Arma 3 and observe the brightness of lights at night.
2. Run Arma 3 with the provided addon (@LightingTest) and observe brightness of lights at night.

The older lighting engine is much better suited to Arma 2 maps, at least while we don't have documentation on LightingNew. See this page for reference:
http://forums.bistudio.com/showthread.php?181226-A2-Island-Lighting-Fixes

Contents of @LightingTest:

config.cpp
class CfgPatches {
class GDSN_LightingTest {

		units[] = {};
		weapons[] = {};
		requiredVersion = 0.1;
		requiredAddons[] = {"A3_Map_Altis", "A3_Map_Stratis"};

};
};

class CfgWorlds {
class DefaultWorld {

		class Weather;

};

class Altis : DefaultWorld {

		class Weather : Weather {
			delete LightingNew;
		};

};
class Stratis : DefaultWorld {

		class Weather : Weather {
			delete LightingNew;
		};

};
};