What Is a Lumen and What is it Doing in my Flashlight?
What is a Lumen? A lumen is a unit of measurement that is used to express how much illumination a source of light provides. We could get all technical here and go through the entire history of lighting measurement starting with whale blubber candles and making our way forward to LED lights, but it’s really far simpler than all that. A lumen is about the equivalent of the amount of light put out by a single birthday candle if you are one foot away from the candle. A lamp that puts out 1 lumen of light is as bright as one birthday candle a foot away. A lamp that puts out 100 lumens is as bright as 100 birthday candles a foot away from you. Differences Between A Lumen And A Watt So what about this lumens per watt thing? A watt is a unit of electrical energy. We measure electrical usage in watts, and pay for our electricity by the number of watts we use. When we talk about lumens per watt (lm/w), we are measuring how many lumens of light are produced for each watt of electrical energy used
