I have a Jax-Z1 flashlight and I am doing some modifications to increase the throw. So far I have tried a de-domed XM-L2 U3 and a de-domed XP-G2 S2 LEDs both on Noctigen copper sink pads. At a distance of approximately 26ft (8m) I get a lux reading of 1760 and 2000 for the XM-L2 and XP-G2 LEDs respectively. I was expecting that the XP-G2 would be better for throw but I am not sure about the mere 13% increase. The XM-L2 had a die size of 4mm2 and at 3A that the Jax-Z1 driver operates it produces about 1000lumens. This results in an die emittance of 250 lumens/mm2. The XP-G2 had a die size of 1.92mm2 and at 3A it produces about 800lumens (see emitter test results) . This results in a die emittance of 416 lumens/mm2 which is 66% higher than that of the XM-L2. If these numbers are correct should I expect to see an 66% increase in lux between a XM-L2 and XP-G2 at the same drive current? Why then am I seeing only a 13% increase?