Key points about lighting
The main advantage of a constant lighting level is that it provides stable lighting performance over the burn time associated with each headlamp. This way, the user knows that neither the luminosity nor the lighting distance will decrease during this period.
To obtain constant lighting, headlamps are equipped with an electronic regulator that maintains luminosity and initial lighting distance, as long as the electric current delivered by the energy source is sufficient. When this source becomes too weak, the light output decreases to a minimum lighting level. This reserve lighting is nonetheless sufficient for finishing a task or for moving around, or to replace the batteries, for example.
Headlamps not equipped with a regulation feature offer very bright light for only approximately 20 minutes. The light output then decreases progressively until the electric power source is depleted.
A uniform light beam ensures maximum visual comfort for the user: lighting is uniform and has no bright point in the center,
no spotting, no shaded zone.
Quality of light source : A perfectly uniform beam can not be obtained without a high-quality, rigorously designed light source and lens.
Absence of bright center point : A bright point in the center of the beam hampers vision, as it blinds the user and obliges him/her to orient the bright point precisely to the zone he/she wishes to see. A perfectly uniform beam eliminates these two flaws: it is not blinding and allows precise viewing of the lit zone.
Absence of visual abnormalities : A uniform beam provides lighting without spots, rings, or shaded zones. These irregularities prevent precise vision and may be disruptive during use, even causing loss of attention.
The choice of shape of the light beam on a headlamp depends directly on how it will be used.
There are three main beam shapes.
The wide beam : It allows diffuse lighting ideal for close-range work.
The mixed beam: It combines a wide part for proximity lighting and a focused part for distance lighting.
The focused beam: It concentrates the light to shine long distances and can be precisely aimed.
Each headlamp provides a lighting level adapted to a specific use.
The lighting level is related to the type of light beam: a headlamp designed for proximity lighting generally provides a wide beam with moderate light output. On the other hand, a headlamp adapted for long-range vision provides a focused beam associated with high light output.
In most cases, headlamps have several lighting modes that allow the user to adapt the light quantity or the shape of the beam to the need. These lighting modes also allow the user to favor greater light output or longer burntime.