On Friday, February 23, 2018 at 7:32:33 PM UTC, Jeff Liebermann wrote:

Please note that I make no claims that a single number will provide
sufficient information for a comparison of lighting suitability,
superiority, performance, visibility, optimum pattern, etc.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

It's anyway pretty rare outside the pure sciences that a single measure of benefit or goodness (or badness) will tell you everything you need know. Practical applications just don't work like that.

Even graphs with a single measure over time are only "singular" for whatever appears on the other axis by the courtesy of assuming time is a constant, even though we've accepted since 1905 that time is a variable like any other.

I'm used to working with huge, expensive statistical studies at the interface of demographics and motivational psychology, to be used in making decisions that will cost (or lose) millions, sometimes billions -- I used to dramatize the risk of carelessness for my people as the number of jobs lost. From a strictly mathematical, theoretical statistical viewpoint, the number of assumptions and guesstimates from experience one is required to make even in a well-studied field can be disturbing, even discouraging to the newbie until he discovers that applied statistics is an art form for high rollers and the super-confident. It's this background that leads me to welcome a meaningful, simplifying, summing shortcut like your square-meter equivalent circle. Together with the distance at which the light from the lamp fills the circle and simple, well-known science, in this case the inverse square root law, it can let you estimate both the spread and the intensity of a properly designed lamp at distances useful to a bicyclist. Pity it won't tell you about the hotspots as well, or nearfield spill from the thickness of the lens, but then you can't have everything.

Yo, Scharfie: I liked the integrating sphere until I discovered you need a guy in a white coat to operate it. I'm allergic to men in white coats: simply too much experience of ticket-punched railroad minds telling me what I can't do, and expecting to be paid after I did it myself. Men in white coats are never worth the rise in blood pressure that accompanies their advent.

Andre Jute
Women in white coats are an altogether different matter