My eyes don't see a big difference on a CR123 but my light meter shows almost twice the output (high vs med). I can tell the difference though.
It seems to help if I give myself a little time to adjust to the medium level first. Otherwise my eyes just seem to want to "protect" themselves...damn that's bright...and it's hard to see the difference. It's easier to see outside shining the light further away. A white wall indoors close up is too overwhelming on both levels to really judge.
From what I've read, a 2x increase in output will only be perceived as about a 25% increase in level by our eyes. I read it's roughly the ration of the cubed roots that we perceive.
The increased output seems of more use lighting up distant objects. The 2X increase will put the same light level on an object at about 1.4 x the distance. (square root of the output difference).
BTW, on a 3.7V protected RCR123 purchase from AW about a year ago, it took 45 minutes to drop into regulation on medium with a total run time of 65 minutes. The output started out the same as the high level as it was direct driving the Cree and dropped constantly over the 45 minutes. A "smart" LiOn charger I use for r/c heli LiPo packs reported it put back 492 mAH.
Mine took a lot long than Chevrofreaks to go into regulation on medium. I suspect I have a Cree with a lower Vf than his. He got 9 minutes. My shorter run time is probably because mine wa consuming more power for longer in direct drive and/or my cell capacity was less than his.
Ok, I must be really, really dumb :-( HOW DOES THE STUPID BELT LOOP ON THE HOLSTER OPEN????
HELP!!! I've pulled and twisted but I can't even see a seam that opens...and I did try searching for info...
I've actually been using a RipOff holster I got for my L1P. It has enough space to hide a spare cell below the light. The velcro flap closure doesn't overlap as far but it's still got an inch and looks secure. I'd just like to use the Fenix holster at times since it's a lot smaller.
Mike
