17/8/25

Why headlamp manufacturers are not being honest about their runtimes.

Headlamp manufacturers typically give outputs of their headlamps in lumens (total light output) and then give a runtime figure for each lumen output level. They often use a standard called the ANSI FL1 standard that was developed by the American National Standards Institute in 2009. This standard states that runtime is defined as the duration of time from the initial light output value (30 seconds after the device is turned on) until the light output reaches 10% of the initial value. Tested with fresh batteries.

Now, to give an examplDiscover thee of what that looks like to our eyes, here are two images taken of the results from a headlamp outputting 660 lux at 2 metres at maximum output and then at 10% (66 lux) of initial output (images supplied by outdoorgearlab.com)

Lux is the amount of light falling onto a surface at a given distance whereas lumens is the total light output at the source. 1 lux is roughly equivalent to the amount of light under a full moon, not very much. Quite a few manufacturers of automotive light bars and driving lights quote figures such as 1 lux at 1 kilometre “These 9″ driving lights pack a real punch, producing 1 Lux at 1km and providing fantastic beam width”. Completely misleading as there is no way to see that level of light at that distance.

Nighttime scene of a paved trail with a yellow centerline, surrounded by trees and a wooden fence, marked with small orange cones and numbered markers, visible in the moonlight.

A dark outdoor trail with a yellow line, reflective markers, and orange cones, surrounded by trees and wooden railings.

It’s very obvious that the right hand image is nowhere near as bright as the image on the left and yet both of these images qualify to be called the same output for a given runtime. This enables manufacturers to legally state unrealistic runtimes.

Below is a runtime graph of a Nitecore UT27 showing the drastic drop in light output soon after turning it on. Image from 1lumen.com

Fortunately, some manufacturers make lights that have regulated outputs which manage the light output in a way that genuinely extends usable light output. One company, Luciferlights luciferlights , manufactured in the Czech Republic, has gone one step further and designed their light circuitry so that the stated runtime extends to 70% of initial output. This is a significantly more sensible and honest way to quantify usable light output. Once their lights reach that 70% point they will automatically drop to the next lower level to regain maximum output at that lower level. You get what you pay for :)

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