tatfiend 

I just ran across this article on the Fenixtactical web site. It explains the new ANSI flashlight rating standards.

https://fenixtactical.com/fenix-ansi-standard.html

Here is a article from Inova which gives more information on individual specifications.

https://inovalight.com/ANSIstandard/

Looking them over they are NOT a good indication of the suitability of a light for bicycle headlight use IMO.

The Lumens rating looks good as the way I read it the measured output is what is required to be listed rather than using LED manufacturers ratings. I am in favor of bicycle headlight manufacturers using this standard.

The runtime is the time until output drops to 10% of initial output. IMO this is too low a light output for useful headlight use time.

The beam distance is to the point where beam intensity is .25 Lux. This is about the same as the full moon's light intensity on Earth on a clear night, totally inadequate for a headlight or a flashlight IMO.

Peak beam intensity is listed in Candelas but the original Fenix article does not say at what distance this is specified. The second Inova one states that this can be listed for 2, 10 or 30 meters distance. I wish they had chosen one distance only as the one sample of output listing I have seen did not indicate distance. It looked to me like the maker chose 2 meters probably.

Having a standard, even if not perfect, is a useful step forward and should allow accurate comparisons to be made between flashlights.

Steve530

Good info. Here's another explanation from Energizer.

garyfloyd

tatfiend, I looked directly at the ANSI/NEMA FL1 specification. Per the specification, the Peak beam intensity is corrected for distance. Therefore, a distance does not need to be defined to the end user. The test distance from the light has to be a minimum of 10 times the largest dimension of the lights lens, or output height or width. So the manufacturer can't just pick the 2,10 or 30 meter distance to get a better number. The specification then uses the inverse sqaure law to calculate the peak beam intensity based on the measured surface light intensity at that distance.

Also, a requirement in the specification calls out that 12 volt DC devices that are only tethered will be powered by 13.8 volt DC power supply for the brightness tests. So for those devices they will be slightly dimmer than advertised.

It seems like a flashlight would have wildly different requirements than a headlight, so I would not this specification as any great help. Seems the like the german headlight requirements are pretty decent (have not read the actual specifications).

tatfiend 

garyfloyd;

Thanks. Most bicycle headlights sold in the USA use flashlight type reflectors and electronics unfortunately. The higher power ones are off road oriented rather than intended for road use and bicycle lighting requirements from the government are minimal.

The German headlight specs per some info I have seen from Germans badly need updating to reflect state of the art LED lighting capabilities, particularly as regards dynamo lights. Items such as minimum acceptable light level are still based on incandescent bulb outputs that a glow worm can provide. Per info from a foreign poster who has seen them the German specs are written such as to be very hard to understand even for a German speaker and apparently no full text English translation is available.

The ANSI specs may not be ideal but they at least address one area that needed it, Lumens output. Ansi requires it be a measured "out the front" value done with an integrating sphere after about 3 minutes of warm-up. It should provide listed outputs a lot closer to reality.