The KL5 has always been the output it was. The rating for the KL5 was refined to be more accurate, appropriate and representative. The KL5 was rated 100 lumens. This is the rating it should always have been.
SureFire have demonstrated that they are quite comfortable with under-rating the output of their products.
Lets say that we pull two flashlights off the shelf and test them.
We find that a 6PL (P60L) is measured with an output of exactly 80 lumens and that an L5 (KL5 or KL5A) is measured with an output of exactly 100 lumens.
(lets put things like changes in output due to thermal management aside for a moment).
The question is whether a person could tell that there was a difference in output between the two beams.
As mentioned this is made significantly more difficult and complicated as a result of the beams having different profiles, and different tints.
I am not sure that it would be all that easy to tell whether there was a 20 lumen difference either side of a 100 lumen output when comparing two flashlights with practically identical beams.
One may also consider whether a nominal rating of 100 lumens conceals output variation from unit to unit of what, 10-20 lumens anyway.
I guess that all it would take is a high performing P60L and an average performing KL5, throw in some tint difference and a difference in beam profile and there is bound to be some head-scratching to work out what is going on - are our eyes playing tricks?
Another issue to consider is the sensitivity of our eyes - not just to light quantity and intensity but also to tint and how ambient and combinations of light impact on our individual perceptions.
Does the flashlight perform its function to the desired measures?
What does the output rating matter? I'm not saying it doesn't - just that it can be counter-productive to get too involved in a number that hides far more variables than can be isolated by even the most dedicated of Flashaholic.
Al
