The maximum luminous flux provided by the lantern.
Luminous flux (denoted in lumens) can be described as the total amount of light produced by an LED or other light source and distributed in all directions where this source shines by itself (without lenses, reflectors, etc.). In fact, this means that the capabilities of the flashlight depend not only on the luminous flux, but also on the angle of illumination (see "Angle of illumination (light)"). For example, a relatively weak stream can be concentrated into a narrow beam, providing good range; and a
large number of lumens will inevitably be needed to effectively cover a wide area.
Note that the coverage angle is not always specified in the characteristics, and even with such data it is difficult to immediately assess the real capabilities of the flashlight. Therefore, for such an assessment, it is best to use information about the actual illumination range (see below), and also take into account the general type of device (see above). For example, for the same number of lumens, a handheld flashlight with a reflector to form a directional beam will give a noticeably greater range than a tourist lamp with 360 ° coverage.
It should also be borne in mind that the
high brightness of the flashlight is far from always justified, and it is worth choosing according to this parameter, taking into account the actual conditions of use. S
...o, when working at short ranges, bright light can become a hindrance: it tyres the eyes and can blind others. In addition, an increase in brightness usually requires more powerful sources of both light and power, and the weight and dimensions of the lantern increase accordingly.
