Beam Distance: Measured in meters, beam length describes how way a flashlight can shine a valuable quantity of mild. The maximum volume of light a flashlight must be equipped to shine to qualify to get a selected beam length is.25 lux (lumens for each sq. meter), or concerning the exact amount of light as provided by the whole moon on a apparent evening. Do you need a led flashlight that may illuminate objects at way distances? If so, you'll be wanting to think about beam distance & also output.   
Peak Beam Intensity:Ought to you closely look at a LED flashlight's beam whilst it shines on the flat surface area, you will detect which the mild is brighter within the middle from the beam. This place is termed the scorching spot, & it represents the flashlight's peak beam intensity. Producers measure peak beam intensity at the bulb by itself & quantify it in candelas.