IgorT said:
I was waiting for something like this.. The more people do this measurement, the more exactly we will know what these diodes are actually capable of! You also have to consider the fact, that not all light can leave the module, because it diverges too fast, and hits the threads on the inner walls.. It takes a lens to bring it all out.
This is great news! I was starting to get worried, when i heard about much lower measurements from others.. But the no optics measurement is very hard to do reliably and with repeatable results anyway...
Can you please describe in a little detail, how you did the no lens measurement?
All this is giving me a lot of hope! A lens with correct coatings should have a transmittance of around 95%!
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Well, the diode is in a kenom barrel, so I just took the lens out and got the head as close to the LPM sensor as I could without touching it. Then, I left it there while holding it for a few minutes and calibrated it to 0, because I didn't want the heat of my hands or barrel skewing the results. Then I just cranked it on and watched the results over about 20 seconds, turned it off to make sure the meter would return to 0 (proving that heat wasn't a factor) and that was that.
Here's my meter: