Originally Posted by
cyccommute
It would be better if all lights had a lumen output on them rather than a wattage rating. It does tell you more information about what you are getting...at least for some unspecified distance away from the light source. Lux would be even better since it tells you more about how much light you are getting where. .
Lumen measurement has NOTHING to do with "distance away from the light source". It's the total light emitted over
time. Lux is the measurement that's distance dependant, as light in a
diverging beam looks dimmer because it's spread out more.
And to digress a bit, your use of a laser beam to illustrate light divergence was ridiculous because lasers typically diverge around 0.05 degrees, and light from bike headlights diverge around 15-20 degrees. Here's another incorrect statement: "If a laser beam were the same size from emitter to a target 50 or 60 feet away, we probably couldn't see it." Really?!? Care to be the subject of that experiment?