lighting question

On pg. 92 under light and darkness, it reads:

"These light sources emit light in a 30' radius, with dim, shadowy light extending about 20' further."
and later,
"Any creatures who cannot see due to darkness or blindness suffer a -4 penalty when attacking. This penalty applies when attacking invisible opponents as well."

My question is, does this mean creatures beyond any illumination, are attacked at a -4, and creatures in dim light are attacked normally OR are creatures beyond illumination untargetable and creatures exposed by dim lighting are attacked at -4?

 

Creatures in dim light are attacked normally. Creatures beyond any illumination are attacked at -4 (once you know they are there).