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 LED's efficiency and how much power it uses.
Ukukhishwa okukhanyayo, okubikwe ku-lumens, kunqunywa inani eliphelele lokukhanya elivela ngaphandle-phambili (i-OTF) ye-flashlight, elihlobene nokusebenza kahle kwe-LED nokuthi lisebenzisa amandla angakanani.