First it was “Candella,” now the hot marketing and technical race is for the most “Lumens.” So just what are lumens and why are they important (or in some cases, unimportant)? How do they relate to brightness and/or intensity? What about directivity and diffusion?
Elzetta flashlights breaks it down “Barney-style” talking about how lumens is a measure of total light output and how that impacts your light selection.
Class dismissed.