Lokacin zabar fitilun titi, fitowar lumen yana ɗaya daga cikin mahimman sigogin fasaha da ya kamata a fahimta. Lumen yana auna jimlar adadin hasken da ake iya gani da tushen haske ke fitarwa. Ba kamar wattage ba, wanda ke nuna kawai yawan wutar lantarki, lumens suna nuna kai tsaye yadda hasken titi yake da gaske.