I'm playing a Ranger, bow-primary, at the moment. I have found that when I equip a bow, I can then equip a lantern. The lantern stays equipped and continues to provide light all through combat. When at first I equipped the lamp, I did get an error message telling me that I couldn't do this with a two-handed weapon, but it didn't cause any effect. I assumed that it would stow my lantern the moment I fired at something. (The same way 2handed weapons work with torches) It didn't.
Oddly enough, if I equip the lantern FIRST, then try to equip my bow, it will not allow me to do so.
The Lantern and the Bow
The Lantern and the Bow
I listen,
I laugh,
I think for a while
As I sit in the dark
And smile.
I laugh,
I think for a while
As I sit in the dark
And smile.