There are many ways to compare the features and specifications of a flashlight, and in this article, we will explain the most common of these features. Light Output Light output, reported in lumens, is determined by the total amount of light coming out-the-front (OTF) of the flashlight, which is related to the LEDâs efficiency and how much power it uses. 1  500+ lumens Typical output of a ultra-high outputLED flashlight. 2  250-500 lumens Typical output of a high-output LED flashlight.