I saw some friends discuss about the Fluxient 3xU2's brightness, some one say it is 1900lumens, someone say it is 3000lumens, and someone say 3800lumens is not ture, I have a Fluxient 3xU2 , I take photo for it , who can tell me the ture brightness? I like its super bright and 8800mAh battery pack long power time.