Maybe it was a dud, and maybe the batteries were bad--but I don't know. I did not purchase the light, I merely test drove it at a sporting goods store. And I know this probably belongs in the cheers and jeers section, but when a light is advertised as white, it should probably be white. And when I buy a light for $160, I assume some serious quality control has ensured me a great product. I know that there is tremendous variation from one LED to the next, or at least there used to be, but I wouldn't expect Surefire to use any "duds" in their process. I mean, I could sit in the back of the store, with 20 L4 boxes open, shining the lights against the wall, trying to find the whitest, and brightest one--but I don't want to. Then, once I have selected one, I would have permanent nagging doubts that mine is not as bright as other L4s. . . I just don't feel doing all that--and I shouldn't have to. I was probably just the batteries.