ScottsoSmith
Newly Enlightened
Hello All,<br><br>I am new to the forum and this is my first post.<br><br>If two different lights have the same emitter (CREE XP-G R5 as an example) and the same battery arrangement (2 - AA as an example), I would expect the lumens * run hours be comparable. They typically are not, however. As an example:<br><br><br>Jet Beam BA20: 270 lumens *1.75 hours = 472.5 lumenhours<br>Fenix LD20: 180 *2.26 hours = 406 lumenhours<br><br>I suppose these differences could be explained by any of the following:<ul><li>Difference in the electrical efficiency of the electronic drivers;</li><li>Difference in optical efficiency of the reflector/lens combination;</li><li>Difference in testing methods;</li><li>Difference in modes (I understand that the high setting on some lights intentionally reduces after a couple of minutes); or</li><li>Bad data (intentional or unintentional).</li></ul><br>What do you think the causes of these differences are? Any info on this topic would be greatly appreciated.<br><br><br><br><br>