Comparison Hikmicro Falcon FH25 vs Hikmicro Thunder Pro TE25

— Binoculars. In its classic form, binoculars require a pair of optical systems, each with its own lens and eyepiece. Thanks to this, you can view objects with both eyes at once, which is quite convenient in itself (you don’t have to close your eyes), and the image looks three-dimensional. The main disadvantage of traditional binoculars compared to monoculars is their higher cost due to their more complex design. Also, such devices are larger, heavier, and if it is impossible to see normally with both eyes at once (for example, with strabismus, or if one eye is missing), all their advantages become irrelevant. At the same time, there is a specific variety - “pseudo-binoculars”: these are night vision devices with one lens, the image from which is sent to two eyepieces. In this case, there is no question of a three-dimensional image, which is why the use of such devices is more limited (in particular, they are considered poorly suitable for driving); but the designs are simpler, lighter and cheaper.

— Monocular. Optical instruments designed for one eye and equipped, respectively, with one optical system with an eyepiece and a lens. They are not as convenient as binoculars because they do not allow for a three-dimensional image and require one eye to be closed. On the other hand, monoculars are much more versatile. Thus, with a slight magnification of such a device, you can observe the situation wit...h both eyes at once, receiving an image from both the NVD and the naked eye; some monoculars can be mounted on weapons, turning a regular sight into a night sight; Another option is to install the device on a helmet and sight through it; and so on. However, the most important advantages over binoculars are compactness, low weight and low cost; In addition, monoculars are suitable even for people with binocular vision disorders.

— Sight. Devices designed for installation on weapons and equipped with appropriate mounts, as well as an aiming reticle of one type or another and a reinforced housing that can withstand recoil. They can be both NVGs and thermal imagers (see “Type”). In fact, such devices are an improved type of optical sights, designed for use in the dark, and in the case of thermal imagers, also in poor visibility conditions (fog, dense vegetation). And some models provide quite advanced functions that make accurate shooting much easier: rangefinder, barometer, compass, ballistic calculator, etc.

- Nozzle. Strictly speaking, this type of optical device is not a night vision device - the attachments themselves do not provide visibility in the dark. In fact, they are additional accessories, the installation of which allows you to expand the capabilities of a full-fledged night vision device. Most attachments play the role of magnetizers - i.e. increase the magnification factor. Such devices are created for specific NVD models, and even from the same manufacturer, not all attachments and devices are mutually compatible; Therefore, you should pay special attention to these points when purchasing.

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 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 size of the area visible in the night vision device from a distance of 100 m — in other words, the largest distance between two points at which they can be seen simultaneously from this distance. It is also called "linear field of view". Along with the angular field of view (see below), this parameter characterizes the space covered by the optics; at the same time, it more clearly describes the capabilities of a particular model than data on viewing angles.

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.

The smallest distance to the observed object, at which it will be clearly visible through the night vision device. For normal use of night vision devices, it is necessary that this distance does not exceed the minimum expected distance to the objects in question; thus, it must be borne in mind that the higher the magnification factor (see above), the greater the focus distance, usually.

The diameter of the exit pupil created by the optical system of a night vision device. The exit pupil is called the projection of the front lens of the lens, built by optics and electronics in the region of the eyepiece; this image can be observed in the form of a characteristic light circle, if you look into the eyepiece not close, but from a distance of 30 – 40 cm.

The practical significance of this parameter is that for normal visibility it must be no less than the size of the pupil of a person looking into the eyepiece. The diameter of the human pupil can vary from 2-3 mm in bright light to 7-8 mm in the dark. Therefore, the larger the size of the exit pupil of the night vision device, the better the visibility, usually; this is especially true with a minimum amount of light, when the brightness of the image is low even when viewed through the device. On the other hand, this feature significantly affects the cost of the device.

The offset is the distance between the eyepiece lens and the exit pupil of an optical instrument (see "Exit Pupil Diameter"). Optimum image quality is achieved when the exit pupil is projected directly into the observer's eye; so from a practical point of view, offset is the distance from the eye to the eyepiece lens that provides the best visibility and does not darken the edges (vignetting). A large offset is especially important if the night vision device is supposed to be used simultaneously with glasses — after all, in such cases it is not possible to bring the eyepiece close to the eye. It is also relevant for devices that can be installed on a weapon: the greater the distance to the eye, the less likely it is to get injured due to recoil.

The type of batteries used by the night vision device for operation. Technically, these can be both replaceable elements of a standard size and built-in batteries. However, in fact, the second option is practically not found, because. it does not make it possible to quickly replace a dead battery with a fresh one — and this possibility is critical for most NVD applications.

As for specific types of batteries, the most common options are:

— CR123. The element that has received the greatest distribution among modern night vision devices. These batteries are similar in shape to the popular AA batteries (see below), but their diameter is larger, and their length is noticeably smaller: 17 and 35 mm, respectively. The operating voltage is 3.7 V, which provides good power, sufficient for normal NVD operation. This led to the popularity of CR123.

— AA. Classic 1.5 V finger batteries. The power of such a power supply is lower than that of CR123, which requires more cells; on the other hand, such batteries are easier to find commercially.

— AAA. "Mini finger" or "little finger" batteries, a smaller version of AA cells. Due to their small size, such elements do not differ in power and capacity, and therefore are used only in relatively simple devices for which compact dimensions are important.