Competence in Light

 

Innovation. Original. Made in Germany.

Busch & Müller is the leading brand for bicycle lighting. All groundbreaking innovations such as stand light, IQ light technology, daytime running light, and much more originate here. The production facility of the family-owned enterprise has always been in Meinerzhagen, Germany, from its founding in 1925 up until current day.

 

How to recognise a good headlight.

Illumination levels of headlights can be measured using different units – e.g. Lux or Lumen.

Busch & Müller gives the light output of headlights using the unit Lux. A Lux value provides the illumination level in relation to its distance from the light source. The value at 10m distance from the light is the legally stipulated distance in some countries, and this has become a market standard. Amongst other factors, this measurement is a deciding factor when considering a headlight, because it states the amount of light on the road. The value Lumen in turn, states how much light is emitted from the headlight at the light source, no matter which direction this light is emitted, so this value includes stray light emitted upwards, that is not much help if you are trying to light up the road in front of you. That is why this value – as excellent as it might sound – can be very misleading.

However, as it stands, even the Lux value provides only partial information about the output of a headlight. Also important is the quality of the light field which is created on the road. Its width, depth, homogeneity as well as its glare-free light/dark boundary are all qualities that cannot be stated using measured data. This means:

The only real way to evaluate a light beam is to take a good look at what it does on the road!


By the way: Some manufacturers cite “visibility from x metres” as a means of evaluating headlamp quality, a rather meaningless value. There is no objective  measuring method, and the safety gain is only an individually perceived factor, because it implies ideal conditions (no interfering light, “clean” air, unhindered visibility, universally identical abilities of human eyesight ...) that in reality do not exist. That is why we forgo quoting a value we consider useless and that only feigns objectivity.