For anyone who didn't see this in the other thread where I also answered it:
The special / elemental weapons give off a larger light radius in rooms (2 squares distance around your character), also maybe not known but you can wield a staff of light and get that effect too!
For the hallways it was a conscious choice to maintain the shorter light distance to keep things more suspenseful and claustrophobic. I wanted the player to still be able to have some of those "oh shit" moments when you are fleeing another enemy and suddenly one is right in front of you
