Comparison Yukon Spartan 3x50 Gen. 2+ vs Yukon Spartan 3x42 WP

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 generation of the image intensifier used in the device with the corresponding principle of operation (see above).

— I. The earliest and, accordingly, the least perfect generation of image intensifier tubes presented on the modern market. Allows relatively comfortable use of night vision devices under the condition of fairly bright "night" lighting (for example, on a moonlit night); in weaker light, active IR illumination is required. At the same time, image intensifier tubes of the first generation are inconvenient when working with point light sources — parasitic illumination appears and the light source “blurs” on the screen. And accidental illumination (for example, hitting the light of car headlights) most likely disables such a device: automatic protection against it is extremely rare, and it is not always possible to close or retract the lens in time. In addition, closer to the edges of the field of view, the resolution of the image in such an image intensifier tube noticeably decreases and distortions appear in it (for example, a square may look like a “cushion”). Simplicity and, accordingly, low cost can be called the unambiguous advantages of the first generation devices. The resource of such a converter is on average about 1000 hours, which is quite enough for infrequent "forays" into nature, but not enough for permanent use.

— I+. An improved and modified version of the...I generation image intensifiers described above. The main improvement was the use of the so-called fibre optic plate — thanks to it, it was possible to make the resolution the same throughout the entire field of view, and also to almost completely get rid of distortion. On the other hand, due to some technical features, such night vision devices at the same magnification turn out to be more expensive (sometimes several times) and bulkier than their predecessors, and they have no advantages over them, in addition to those described above. Because of this, the improved version of the first generation image intensifier is less common than the original.

— II. The key difference between the second generation image intensifier tube and its predecessors was a two-stage light amplification scheme: in the traditional way, as in the first generation, and then using a microchannel plate. This made it possible to significantly increase the degree of amplification, which made it possible to use night vision devices even on a dark night — by the light of stars in light clouds. In this generation, it was also possible to ensure uniform image quality over the entire field of view, to get rid of significant spurious flare (a point light source in the field of view almost does not blur). In addition, automatic protection against backlight has become almost mandatory for such devices, and the resource, compared to the first generation, has increased significantly — up to 3000 hours in some models. However the cost of night vision devices with such converters has increased significantly.

— II+. Improvement of the second generation transducers (see above), aimed, in particular, at reducing the size of night vision devices and further improving the quality of the "picture" (albeit at the expense of some reduction in the light amplification factor). Note that under this designation, both the “original” generation II + and its improved version Super Gen II + can be hidden. The latter option is able to provide a visibility range almost at the level of the image intensifier tube of the III generation, and at the same time it costs much less (although still more expensive than the device of the original generation II +).

— III. In the third generation of image intensifier tubes, manufacturers used an innovative material in the design of the photocathode, which made it possible to significantly increase the sensitivity (both general and in the IR range). Converters of this generation are capable of operating in extremely low light, provide a clear, high-quality image with high detail and have a resource of about 10,000 hours; thus, they are the most advanced on the modern civilian market. However, the main users of such equipment are the military and representatives of special services: it is for them that the described advantages are critically important, and III generation image intensifier tubes cost 1.5 – 2 times more expensive than II + (which are not cheap in themselves), which makes it difficult for civilians to use such devices. Another disadvantage of converters of this type is considered to be a rather significant sensitivity to side illumination.

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 visible image created by the night vision device. Indicated by the number of lines (strokes) per millimetre; the higher this indicator, the more detailed the image is capable of creating the night vision device, the better small details will be visible on it. However such devices will cost accordingly.

In models with an image intensifier tube (see "How it works"), the resolution is highly dependent on the generation of the transducer.

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 presence in the design of night vision devices of an IR emitter(see above), operating in a completely invisible spectrum.

One of the features of modern lighting devices (including infrared ones) is that none of them is capable of producing waves of exactly the same wavelength — some part of the radiation will inevitably capture neighboring ranges. Because of this, situations arise when the illuminator, the main power of which is concentrated in the IR spectrum, also emits visible light. It looks like a dim red glow; it is not strong enough to illuminate surrounding objects to the naked eye, but is clearly visible in the dark and can unmask the user. Radiators with an invisible spectrum, as the name implies, do not have this drawback. Therefore, if you are looking for night vision devices for situations in which stealth is important — for example, for hunting — it makes sense to choose among models with this function. However note that the illumination range of such emitters is somewhat less than that of visible ones.

Usually, "invisible" emitters have a wavelength (see above) of at least 800 nm.

— Video output. The presence in the NVD design of an output that allows you to broadcast an image from the device to an external device — for example, a laptop. Thus, you can view the "picture" on a large display and record video even if the night vision device does not have its own video recorder (see below); and if it is available, you can broadcast not only the image in real time, but also the captured materials. The specific video output interface may vary, but most often the signal is transmitted in analogue format.

— Built-in video recorder. The presence of its own video recorder in the design of night vision devices. This allows you to use the device as a video camera, capturing everything that falls into the field of view on video; at the same time, such recording does not require additional equipment, in contrast to working with the video output described above. Video, usually, is stored on a memory card, and in many models it is possible to view the recording directly on the device itself.

— Switching observation modes. The ability to switch observation modes means changing the colour features in the “picture” visible to the user. So, thermal imagers (see "Type") with this function support at least two classic modes "white hot" (the warmer the object, the brighter it is) and "black hot" (the warmer, the darker); in addition, additional format...s can be provided, such as highlighting especially warm objects in red. In classic night vision devices, switching modes usually involves changing the colour tone of the visible image — for example, from classic green to red or black and white. And additional features may include, for example, a high contrast mode.

— Filling with gas. This feature implies the presence in the body of a filler in the form of an inert gas — for example, nitrogen — containing a minimum of water vapor. Such an environment does not oxidize the parts in contact with it, and the “dryness” of the filler also prevents fogging of the optics from the inside during temperature changes. Note that a kind of “side effect” of filling with gas is dust and water protection (see below), since the cases of such devices, by definition, must be airtight.

— Dust-, water protection. The presence in the design of night vision protection against dust and moisture, which prevents the ingress of contaminants on sensitive components. This feature is almost mandatory if you plan to actively use the device in the open air — for example, hunting. Note that the level of security can be different, and a high degree of protection usually means a high price. Therefore, when choosing, it makes sense to clarify the parameters claimed for each specific model and correlate them with your real needs.

— Impact protection. This function involves the use of various means — strong elastic body materials, shock absorption systems, etc. — which prevent damage to the sensitive components of the device during shock and shock. The degree and features of shock protection can vary markedly: usually, such models can withstand drops of at least 1.5 m, but in some cases this figure may be more. Note that for installation on firearms, special protection against recoil is required, which not all shock-resistant devices have.

— Angled eyecups. The presence of beveled eyecups (or one eyecup, in the case of monoculars — see "Type") in the design of night vision devices. The elongated part of the eyecup when working with the device is located on the outside of the eye, almost on the temple; due to this, it provides additional protection for the eye — primarily from extraneous "flare" that interferes with normal viewing of the image in the eyepiece. At the same time, such models do not go well with glasses: at best, the eyecup will have to be turned up, negating all its advantages, and in some devices this is not even possible.