Copyright 2004 Ken Greenebaum
Measuring Intensity
nCandelas per square meter
nLight generated by a hypothetical candle
n0.00003 Moonless overcast night
n0.003 Moonless clear night
n0.03 Moonlit clear night
n3 Twilight
n30 Very Dark Day
n300 Overcast Day
n3000 Clear Day
n30,000 Day with sunlit clouds
nFrom: Lighting Handbook