From the Brunton website: Lux rating: 7 (Lantern Mode) - 35 (Flashlight Mode) @ 2 meters Not from the Brunton website: Comparing the light from different flashlights, headlamps, etc. can be a tricky business. The best way is by comparing diagrams that show light intensity and spread at different distances from the light and a different distances from the centre of the beam. What a lux measurement really tells you is how good a device is at projecting light over a distance, not the overall brightness or quantity of light produced. This website has the best explanation I've found so far (most of them are so confusing it's not even funny): http://www.flashlightreviews.com/features/lux.htm. Bascially, this device produces 7 lux (lumens/square metre) in lantern mode and 35 lux in flashlight mode, measured at a distance of 2 m from the light, in the centre of the beam. BUT that doesn't tell you anything about how wide the beam is or how the light intensity changes towards the outer edges of the beam. So...there's a whole bunch of information for you, but in terms of how that helps you pick a light...? Unless you have something to compare to that uses the same measurement, it doesn't. It would be nice if Brunton would give us the beamshot diagram...