Number of diodes
The number of LEDs (see "Lamp type") provided in the design of the lantern.
At first glance, the more LEDs, the more powerful this model. However, in fact, things are not so clear cut. Firstly, one high-end LED may well provide more light output than several inexpensive diodes. Secondly, modern luminaires can use both traditional LEDs and arrays of numerous miniature diodes on a common basis. Such arrays can be implemented using SMD technology or more advanced COB; the differences between these options are described in more detail in the Diode Model section, here we note that a solid SMD or COB plate is also considered to be 1 LED — despite the fact that in terms of luminosity it can exceed conventional LEDs by several times, or even orders of magnitude.
Thus, it is hardly worth directly evaluating the brightness and efficiency of the flashlight by this parameter. But what the number of diodes often directly affects is reliability: most “repeatedly charged” lamps are able to continue working even if some of the diodes fail. In addition, in some types of flashlights — in particular, tourist models and hand-held diffused lamps (see "Type") — each LED illuminates a separate sector, and together they cover a full 360 ° horizontally.
Max. luminous flux
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. So, 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.Lighting range
The maximum range at which the flashlight provides any effective illumination of objects. Different manufacturers have different criteria for this efficiency when measuring ranges, and therefore it is only possible to unequivocally compare among themselves in range only models of one manufacturer. At the same time, this parameter allows us to compare models from different manufacturers with some certainty: for example, flashlights with a lighting range of 15 m and 100 m will clearly belong to different range classes, regardless of manufacturers.
Note that the range of illumination depends not only on the maximum luminous flux provided by the lantern (see above), but also on the features of its design: the narrower the beam is provided by the reflector of the lantern, the greater the range will be, and vice versa — scattered light does not spread far. Some models allow you to adjust the beam width depending on the requirements of the situation (for more details, see "Adjusting the focus").
It is also worth bearing in mind that models with the same claimed lighting range can cover different spaces. For example, a hand lamp (see Type) with a reflector diameter of 20 cm will be able to provide a wider beam than a conventional hand lamp with a 5 cm reflector. And although in both cases the objects that fall into the light spot will be illuminated in the same way, however, in the first case, the size of the spot itself will be larger, and the actual efficien...cy of the flashlight will be correspondingly higher (in light of the fact that it is easier to "feel" individual objects with a wide beam, especially at a considerable distance).
Battery capacity
The capacity of the battery provided in the design or delivery of the flashlight.
Theoretically, a higher capacity allows to achieve greater battery life, but in fact, not everything is so simple. Firstly, the actual battery life will also depend on power consumption — and it can be different even in models with the same luminous flux (this is due to the difference in the characteristics of individual LEDs). Secondly, the physical features of the designation in milliamp-hours (mAh) are such that only batteries with the same nominal voltage can be directly compared by this indicator (in other cases, indicators must be recalculated using special formulas).
In light of all this, we can say that battery capacity is more of a reference than a practically significant parameter. So, in some cases, it allows you to compare different models of flashlights with each other, but only very approximately. For example, a device with a 1600 mAh battery will definitely have a longer battery life than a model with an 800 mAh battery that is similar in brightness, lamp type and “weight category”; but how much battery life will be higher is impossible to say for sure. So, in order to assess the practical capabilities of a flashlight, it is worth focus on more "close to life" characteristics — first of all, on the directly claimed maximum battery life (see above), as well as battery life indicators in different modes indicated in the manufacturer's documentation.
