On Fri, Feb 5, 2010 at 5:44 PM, Chris McSweeny wrote: > So the perceived brightness for the same power > input isn't actually better. Ah, earlier when I was asserting that pulsing a LED can make it appear brighter I was not talking about efficiency. I was talking about significantly overdriving an LED during the pulse. For instance, if an LED is rated for 10mA you may be able to drive it with 2A pulses at a 5 or 10% duty cycle, and it will appear brighter than simply running it steady state at 10mA. In this case we don't care about energy efficiency, and I don't think the press release mentions that it's energy efficient to drive it in such a manner that it attains its maximum lumens. Whether it's energy efficient or not is irrelevant. The question for this particular press release is how do they measure the lumens, and under what drive conditions does the LED emit that power. Or, in other words, a discussion on energy efficiency would be a separate discussion altogether - while important in general, it's not what the OP wanted to know. -Adam -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist