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).
This feature is indicated for flashlights whose housings have an increased degree
of dust and moisture protection. The degree of such protection may vary: for example, some models can easily withstand heavy rain, others “survive” being caught in a sea wave, and the most advanced ones can even be used when diving with scuba diving (see “Type -
For diving ”). The features of protection should be clarified in each case separately; however, if you need a flashlight that can withstand adverse conditions, you should definitely look for it among the models that explicitly state dust and moisture protection. Such models will be useful primarily for those who often have to work in difficult environments: climbers and other “extreme” tourists, rescuers, military personnel, sailors, etc.
The level of protection is indicated by two numbers according to the IP standard (
IP65,
IP66,
IP67...). The first number corresponds to dust protection (maximum 6). The second number indicates the degree of protection from water; here in protected models, level 7 (the ability to immerse under water to a depth of 1 m for half an hour) or 8 (the ability to work for long periods of time under water at a depth of more than 1 m) is usually found. Thus, the maximum degree of protection according to this standard is
IP68, completely sealed. There is also a marking like
IPX8, where the first digit is not indicated - this only means that the flashlight has not been officially certified for dust resistance. In the above example, this is not necessary - water resistance 8 automatically means a sealed case, impenetrable to dust.
It is worth considering that even completely sealed models may have different restrictions on the maximum immersion depth. So if you are going to intensively use the flashlight underwater, you should make sure that it can withstand diving to the planned depth.
