Comparison Yukon Sentinel 3x60 vs Yukon Sentinel 2.5x50

The magnification provided by the scope. This parameter indicates how many times the image of any object in the field of view will be larger than that visible to the naked eye. For models with the ability to change the ratio (see below), the entire available range of adjustment is indicated.

Modern sights can be produced in a wide variety of magnifications, the only exceptions are collimators (see "Type") — they usually give a magnification of 1x, that is, in fact, do not change the visible image in any way; higher values are extremely rare and usually do not exceed 5x. In other types of sights, the maximum magnification from 2x to 5x means that this model is designed for very short distances of application. In turn, the most "far-sighted" devices can provide an increase of 17 – 20x and even more.

Note that a high magnification not only allows you to better view distant and small objects, but also narrows the field of view. With this in mind, the main criteria for choosing a sight by magnification are the expected distances of use, as well as the size and type of targets. Detailed recommendations on this matter for different situations can be found in special sources. And here we note that the degree of magnification significantly affects the cost of the sight — both in itself and due to the fact that larger (and, acco...rdingly, more expensive) lenses are desirable for "long-range" optics. At the same time, a low magnification is not necessarily a sign of a cheap device — in itself, it only means that the sight is designed for short distances and a wide field of view.

As for models with variable magnification, the wider the adjustment range — the more advanced and versatile the device is, the lower the likelihood that there is no suitable setting for a particular situation. On the other hand, expanding the range complicates the design, making it more expensive and less reliable.

The diameter of the objective is the front lens of the sight. This parameter is also called "aperture".

This parameter is important primarily for optical sights and their specialized varieties — "night lights" and thermal imagers (see "Type"). The larger the lens, the more light enters it, the higher the image quality and the more efficient the device will work in low light, but the more expensive such optics will cost. It is worth noting here that the requirements for the aperture also depend on the degree of magnification: in other words, especially large lenses are not required for low magnifications. Therefore, relatively small entrance lenses, with a diameter of 25 – 35 mm and even less, are found in all price categories of classical optics — from low-cost to top. And you can compare by aperture only models with the same maximum magnification, and even then it’s very approximate — it’s worth remembering that image quality also depends heavily on the overall quality of the sight components.

In turn, for night sights, especially those based on image intensifier tubes (see "The principle of operation of night vision devices"), a large aperture is fundamentally important. So a diameter of 36 to 45 mm is considered very small for such devices and is found only in some digital models, while most nightlights are equipped with lenses of 46 mm or more.

As for collimators, the size of the space that enters the scope depends mainly on the aperture. Moreover, the actual visible size can be changed by setting the sight closer or farther to the eye — the principle of operation of collimators makes this possible. Note also that for models with lenses of a rectangular or similar shape, the size of the lens is usually indicated diagonally.

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 sight is planned to be used simultaneously with glasses — after all, in such cases it is not possible to bring the eyepiece close to the eye, and it must be at some distance from the glasses so as not to hit the glass due to recoil.

The diameter of the area visible through the sight 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". This indicator is more convenient for many users than the angular field of view (the angle between the lines connecting the lens and the extreme points of the visible image) — it very clearly describes the capabilities of the device.

In sights with magnification adjustment (see above), both the entire range of width — from maximum to minimum — or only one value of this parameter can be indicated. In the latter case, the largest width of the field of view is usually taken, at the minimum magnification.

— Dust-, water protection. Protected housing that prevents dust and moisture from entering the delicate components of the sight. This feature is highly desirable if the sight is planned to be used in adverse conditions — for example, during a long hunting trip, where there is a chance of encountering bad weather. However it is worth considering that the specific degree of protection may be different, it should be clarified according to the documentation for the sight. However, almost all “protected” models are able to endure rain at least without problems.

— Impact protection. Special protection that prevents damage to the sight during impacts and shocks — for example, by accidental falling or contact with a foreign object. The effectiveness of this protection may vary for different models, but in most cases it at least allows you to transfer the fall onto a hard surface from a height of 1 – 1.5 m. with a high probability it will turn out to be useless — the impact force will be much greater than that for which the device was originally designed. In addition, after any strong impact, the sight will have to be re-aligned. However, additional protection anyway improves the overall strength and reliability of the device.

— Filling with gas. A feature that is found exclusively in sights with closed cases (see "Design"). Such cases are made airtight, and th...e internal space in them is filled with an inert gas — for example, nitrogen — with a minimum content of water vapor. Thanks to this, the optical elements of the sight do not fog up from the inside, and metal parts do not oxidize due to contact with moisture. In addition, such an air-tight housing, by definition, is also dust and moisture resistant (see above).

— Rangefinder. A device that allows you to measure distances to objects visible in the scope. Do not confuse this function with rangefinder markings and other similar reticles (see “Reticle type”): in this case we are talking about a separate device, usually in the form of a laser rangefinder. Such equipment greatly simplifies measurements: there is no need to bother with special calculations for the angular dimensions of visible objects, just one click of a button is enough, and the accuracy of laser devices is very high — on the order of several centimeters at distances of hundreds of metres. The main disadvantage of this feature is the high cost; in addition, additional equipment increases the weight and dimensions of the sight. Therefore, built-in rangefinders are found exclusively in professional models designed for high-precision shooting.

— Level. A device that allows you to control the deviation of the sight (and, accordingly, the weapon) from the horizontal position — namely, the tilt to the right / left. Such a need arises primarily with high-precision shooting: even a slight slope, imperceptible to a person, can give a significant deviation, especially at a great distance. Levels may have a different design and principle of operation, but they are always set so that the shooter can see such an indicator at the same time as aiming. For example, in optics (see "Type"), a bubble bulb is placed above the lens or to the side of it, while in "night lights" and thermal imagers, data from an electronic sensor is projected directly into the eyepiece.

— Lantern. A flashlight mounted directly into the body or on the body of the sight. A rather specific function that is rare: at distances where optics are mainly used, a searchlight is needed, for "night lights" an IR illuminator is relevant (see below), collimators are more convenient to use with a separate underbarrel or hand "tactical" flashlight. However, the built-in lamp cannot be called completely useless. So, in optical sights, it is usually combined with a laser designator (see below), allowing you to effectively use the laser in low light conditions. And in the case of a collimator, the LEDs built into the frame are more compact than a separate underbarrel flashlight (which, moreover, can not be installed on every weapon that is compatible with a collimator).

— Laser designator(LTC). Device for quick aiming at short distances. The idea of such a device is extremely simple: a laser beam shows where the weapon is aimed, creating a clearly visible mark at the point of impact. This allows you to shoot accurately, even without looking into the main sight — including "from the hip" and from other emergency positions, which is especially useful in situations requiring maximum reaction speed. LCC is relevant only at minimum distances, but this is not a drawback, but a feature that can turn out to be a definite advantage. For example, a "laser" can be a great addition to a telescopic sight, which by itself is useless at short distances.

— Compatibility with night vision devices. Possibility of using the sight with separate night vision devices. Most often, this feature is found in collimator sights (see "Type") — it means that the brightness and colour of the collimator mark make it possible to clearly see it even through night vision devices. But optical models with such compatibility are extremely rare: firstly, it is technically difficult to implement, and secondly, for sniper shooting in the dark, there are specialized night and thermal imaging sights that are more convenient and effective than a combination of night vision devices with classic optics.

The range of ambient air temperatures within which the scope maintains normal performance. Note that going beyond this range does not always mean failure and failure; however, correct operation and proper accuracy in such cases are not unambiguously guaranteed.

As for specific figures, most modern scopes have a temperature range wide enough to normally tolerate not only indoor use (for example, in a shooting range), but also outdoor use in a temperate climate during the warm season — from mid-spring to mid-spring. autumn. But the possibilities of application in more extreme conditions — both in frost and in extreme heat at a level of +40 °C and above — should be specified separately.

We also emphasize that even the most “heat-resistant” models cannot be exposed to prolonged exposure to the sun: under direct sunlight, the body of the device can become very hot even in very cold weather.

The total length of the sight.

This parameter is important primarily for optical sights (see "Type"). Such devices can be quite large — from 20 – 30 cm in the most compact models up to 40 cm or more ; and the distance from the eyepiece to the eye when aiming must be strictly defined. So before buying, it's ok to clarify whether it will be possible to correctly place the selected model on the weapon. But collimators, even the largest ones, are very compact, usually there are no problems with their installation, so in such models the length does not play a special role.