Rescue - Petzl

NIGHT TRAIL RUNNING
Declining lighting or constant lighting?
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Contents
© Lafouche
In 2000, the TIKKA was introduced as the first compact
LED headlamp. Since then, technology has continued to
evolve: as a reference, the first TIKKA provided 9 lumens
of maximum lighting. Today, the TIKKA XP 2 delivers
80 lumens of lighting power in maximum mode. LEDs have
also allowed headlamps to become extremely light and
compact, and characterized by very long lighting duration.
While the LED revolution has been significant in terms of
power, the technology of the batteries themselves has
not evolved proportionally. Concretely, the more powerful
the LEDs become, the more energy they consume.
Consequently, in a classic energy management model, the
brightness of the headlamp will rapidly decrease in declining
mode. Headlamps that allow constant lighting offer an
alternative for maintaining brightness.
Declining lighting
Most compact headlamps provide brightness in declining
mode, i.e. with an uninterrupted decline in power from the
moment they are turned on. This drop in lighting power varies
depending on the LEDs, the type of batteries, etc.
For example, with a TIKKA XP 2 the light quantity is 80 lumens
when first turned on using new batteries, and it is 54 lumens
after the first half hour of use. After 80 lhours, the light output is
considered unusable (below 0.25 lux, the equivalent of the light
emitted from a full moon on a clear night).
Headlamps with declining lighting offer longer lighting duration
and high light output at the beginning of use. They are a
reasonable compromise between light output and battery
life. However, for many activities it is more important to have
constant light quantity over a designated period of time.
Constant lighting
With this type of lighting, the lamp's discharge cycle is treated
differently: the light output is constant during the specified
battery life of the headlamp (outside of reserve lighting).
With a TIKKA XP 2 with its rechargeable CORE battery
configured for constant lighting, you will always benefit from
the same quantity of light, whether you go for a one-hour or a
four-hour run.