ToME: the Tales of Maj'Eyal

Playing ToME 4b18.

Wielding Moon dagger and a scorching brass lantern I get the expected light radius of one.
Activate stealth and now my light radius goes UP to two.

Do you have heightened senses? If your infravision is 8 or higher you'll have a 'light' radius of 2 without a light source.

Hmm, yes, heightened senses 2/5, radius 7.