What is the difference between Lumens, Lux, Candlepower and Peak Beam Candlepower?
After compiling these notes and trying to get my head around all the information, I decided to put the summary at the beginning so that you can decide now if you want to torture yourself further. Summary The lumens rating provides a more meaningful measurement to consider when comparing and selecting a torch. Candlepower ratings may be impressively large numbers but they are misleading and you may be bitterly disappointed if you do not also take the lumen rating into account. Peak Beam Candlepower is a measure of brightness at a specific point. The lumens rating tells us the total amount of light present in a beam pattern. I have had customers who have been bitterly disappointed with million candlepower torches they have purchased from their local hardware. A. Lux is the unit of illuminance and is measured in Lumens/ sq M . It quantifies the capacity of the torch to project light over a distance. Lux is only measured at the very centre of the beam. For example, a 1 watt luxeon LED with
