I have noticed that there is an apparent bug with the portable gas lamp. This was noticed while in 1st person only.

I had a damaged portable gas lamp with a small gas canister attached. When turned on, the light source appeared to be coming from the base of the lamp where your character was gripping it rather than the lamp shade. Also, the light source appears to be centered on your character rather than the lamp

I subsequently acquired a pristine lamp and swapped the gas canister to the new lamp. When the pristine lamp is turned on and your character is in combat stance, arms up, the light is now emanating from the shade but the light's effect on the environment begins to fade to black (at night) leaving the lamp shade illuminated but the remainder of your screen black (night) or dark (daytime). The pristine lamp only provides light if your character is not in a combat stance.