Comparison Yajia YJ-2886 vs Yajia YJ-2829

Luminous flux (measured in lumens) can be described as the total amount of light produced by an LED or other light source and emitted in all directions the source shines by itself. In practice, this means a flashlight’s capability depends not only on luminous flux but also on beam angle. For example, a relatively weak flux can be concentrated into a narrow beam to achieve good throw; while effectively covering a wide area will inevitably require a large number of lumens.

Peak luminous flux is the short-term maximum brightness a light source can deliver with a fresh battery and low temperature, usually in Turbo mode. It’s used to gauge instantaneous burst output. Unlike sustained (long-term) luminous flux, the peak lasts seconds or minutes and then drops due to heating down to High mode, so for real-world use it’s more important to understand how many lumens a flashlight can maintain steadily. You can see this with EDC models: a stated 2000 lm is impressive for a quick outdoor search, but for a long walk the device will switch, say, to 1000 lm, keeping a comfortable body temperature and solid runtime.

It’s also worth keeping in mind that high flashlight brightness is far from always justified, and you should choose this parameter based on real conditions of use. At short distances, very bright light can be a hindrance: it tires the eyes and can dazzle people nearby. In addition, increasing brightness usually requires more powerful sources of both light an...d power, so the flashlight’s weight and overall dimensions go up.

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).

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.

The time to fully charge the battery, which is equipped with a flashlight, from a standard charger (when using other batteries or a "non-native" charger, this time can vary both in one direction and in the other direction).

An indicator that indicates the level of charge of the battery installed in the flashlight. The design and functionality of such an indicator can be different — from a simple LED that changes colour and/or mode of operation depending on the state of the battery, to an LCD display that can display a specific charge level. However, anyway , the charge level indicator makes it easier to monitor the state of the battery and reduces the likelihood of being left without light at the most inopportune moment.

The ability to operate the flashlight in power bank mode — an external battery for various portable devices, primarily smartphones and tablets.

The Power bank mode allows you to recharge portable gadgets from your flashlight's own battery. It can become a real salvation in nature or on the road, when there are no sockets and other power sources nearby, and you need to charge the gadget urgently (for example, if we are talking about a phone used as the main means of communication). Of course, such charging wastes part of the battery energy and reduces the battery life of the flashlight itself. However, models with this function, usually, use fairly powerful batteries with a good supply of energy, and their battery life remains very decent even after working in Power Bank mode. And some flashlights even have built-in limiters that do not allow you to discharge your own battery “to zero” when charging an external device.

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.