Comparison Guide IR510X vs Guide IR510C

The greatest distance at which a night vision device is capable of detecting individual objects.

The methods by which manufacturers determine this parameter may vary in detail, but the general principle is the same. Usually, the distance is indicated at which, with an illumination of 0.05 lux (a quarter of the moon) and a medium-contrast background, a rather large object can be seen — for example, a human figure with a height of about 170 cm is most often taken. of this object, but only to notice the very fact of its presence. Simply put, a detection range of, say, 200 m means that “something that looks like a person” can be seen in such a device at a distance of 200 m, but individual parts (head, hands) cannot be disassembled.

It is also worth noting that in fact this parameter is highly dependent on the characteristics of the situation. For example, a dark object on a very light background will be visible further, and on a dark one it may not be noticeable even up close; a similar phenomenon is observed for thermal imagers (see "Type"), only regarding the difference in temperature, and not in colours.

The degree of image magnification that a night vision device is able to provide without digital image processing, solely due to the optical system. Such an increase is considered to be preferable to digital, because. it does not impair the clarity of the visible image; and for models based on image intensifier tubes (see "How it works"), this is generally the only available option.

Theoretically, the higher the magnification, the greater the detection range (see above), since a powerful increase allows you to see smaller objects. However, it does not always make sense to chase the maximum performance. The fact is that with increasing magnification, the angular field of view decreases and the minimum focus distance increases (see both below), which can create problems at close range. It is also worth noting that a high degree of magnification adversely affects the luminosity of the entire system — as a result, the actual detection range in complete darkness may be higher for a device with a lower magnification, because. it "catches" more light. Yes, and this parameter affects the cost accordingly.

Note that night vision devices, unlike classical binoculars and monoculars, most often have a fixed magnification. Models with the possibility of smooth adjustment are almost never found, and the only option is to use additional nozzles (see "Form factor").

Now on the market are night vision devices with the following optical zoom: 1x, 2 – 3x, 3.1 – 4x, > 4x

The diameter of the entrance lens that the lens of the night vision device is equipped with.

This parameter is one of the most important for any optical device, including night vision devices: the larger the lens, the more light (or infrared radiation) enters it and the more sensitive the optics are, all other things being equal. The downside of this is an increase in the size, weight and cost of the device. In addition, do not forget that various tricks and additional technologies can be used in the design; therefore, by itself, a large lens is far from always an unambiguous indicator of a high class.

The resolution of the matrix installed in the thermal imager (see "Type") or digital night vision device (see "Operating principle"). Usually specified in pixels horizontally and vertically, for example 640x480.

On the one hand, the higher the resolution, the clearer and more detailed the image will be. On the other hand, increasing the resolution without changing the matrix size means that less light will fall on each pixel, which negatively affects the detection range (see above) and leads to the appearance of noise. Therefore, the resolution of receivers in modern NVDs is small - in terms of conventional megapixels, it rarely exceeds 0.3 MP. And it hardly makes sense to compare different models by this parameter, because the actual quality of work also largely depends on the size of the receiver, the features of signal processing, etc.

The frame rate on the screen of the thermal imager (more precisely, on the display visible to the shooter through the eyepiece). The higher this frequency — the smoother and less jerky the image is, the better the thermal imager is suitable for looking at fast moving objects. On the other hand, this indicator directly affects the price of the device and reduces its battery life, because. a high frame rate requires a powerful (and therefore expensive and high consumption) electronic hardware.

The angle of view provided by a night vision device — that is, the angle between the lines connecting the observer's eye with the two extreme points of visible space. Wide viewing angles allow you to cover a large area, but the magnification factor (see above) is low; in turn, increasing the magnification leads to a decrease in the field of view.

Availability of dioptric correction function in NVDs.

This function will be very useful for those who wear glasses due to myopia or farsightedness. By setting the required number of “plus” or “minus” diopters on the adjustment scale, such a customer will be able to look into the eyepiece with the naked eye and see a clear picture - the necessary correction will be provided by the optics of the device. This is much more convenient than watching through glasses.

Note that the correction range is usually small, and in case of serious visual impairments, the capabilities of the optics may not be enough; but such situations are still quite rare.

The longest time that the device is able to work continuously from fresh batteries without replacing / recharging them. It should be taken into account that manufacturers usually indicate this time for perfect conditions: high-quality batteries, low brightness of the visible image, operation without the use of IR illumination, video output and video recorder (if available, see "Additional"), optimal operating temperature (see below) ) etc. Therefore, in fact, the time of continuous operation may well be lower than stated. Nevertheless, this parameter makes it possible to both evaluate the battery life of individual devices and compare them with each other.

Ambient air temperature range at which the night vision device will be guaranteed to maintain normal performance. This indicator is very important, given that such devices are most often used outdoors, where the temperature variation can be very large. Of course, when choosing, you should take into account the conditions in which you plan to work with the device — for example, it hardly makes sense to specifically look for a frost-resistant model for hunting in the summer. But in general, the wider the operating range, the higher the overall reliability of the device, the less sensitive it is to adverse climates.

It is worth noting that going beyond operating temperatures does not necessarily lead to instant failure; however, even with the preservation of operability, the probability of failure increases many times, and such cases are not covered by the manufacturer's warranty.