Comparison Hawke Vantage IR 3-9x40 Mil Dot vs Hawke Vantage IR 2-7x32 AO

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 diameter of the exit pupil created by the optical system of the sight.

The exit pupil is called the projection of the front lens of the lens, built by the optics 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 diameter of this circle can be calculated by dividing the lens diameter by the multiplicity (see above). For example, an 8x40 model would have a pupil diameter of 40/8=5mm. This indicator determines the overall aperture of the device and, accordingly, the image quality in low light: the larger the pupil diameter, the brighter the “picture” will be (of course, with the same lens quality, because it also affects the brightness).

In addition, it is believed that the diameter of the exit pupil should be no less than that of the pupil of the human eye — and the size of the latter can vary. So, in daylight, the pupil in the eye has a size of 2-3 mm, and in the dark — 7-8 mm in adolescents and adults, and about 5 mm in the elderly. This point should be taken into account when choosing a model for specific conditions: after all, high-aperture optics are expensive, and it hardly makes sense to overpay for a large pupil if you need a scope exclusively for daytime use.

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.

A complex indicator that describes the quality of any optical system (including sights) at dusk — when the lighting is weaker than during the day, but not yet as dim as in the deep evening or at night. It is primarily about the ability to see small details through the device.

The need to use this parameter is due to the fact that twilight is a special condition. In daylight, the visibility of small details is determined primarily by the magnification of the optics, and in night light, by the diameter of the lens (see above); at dusk, both of these indicators affect the quality. This feature takes into account the twilight factor. Its specific value is calculated as the square root of the product of the multiplicity and the diameter of the lens. For example, for an 8x40 scope, the twilight factor would be the root of 8x40=320, which is approximately 17.8. Models with adjustable magnification (see above) usually indicate the minimum twilight factor corresponding to the minimum magnification.

The lowest value of this parameter for normal visibility at dusk is considered to be 17. At the same time, it is worth noting that the twilight factor does not take into account the actual light transmission of the system — and it strongly depends on the quality of the lenses, the use of antireflection coatings (see below), etc. Therefore, the actual image quality at dusk for two models with the same twilight factor may differ markedly.

One of the parameters describing the quality of visibility through an optical device in low light conditions. Relative brightness is denoted as the diameter of the exit pupil (see above), squared; the higher this number, the more light the sight lets through. At the same time, this indicator does not take into account the quality of the lenses and their coatings used in the design. Therefore, comparing two sights in terms of relative brightness is only possible approximately, because even if the values are equal, the actual image quality may differ markedly. Also note that it makes sense to pay attention to this parameter only if the sight is planned to be used at dusk.

As for specific values, in the "dimest" models, the relative brightness does not exceed 100, in the most "bright" it can be 300 or more. Detailed recommendations regarding the choice of this parameter for certain conditions can be found in special sources. Here it is worth mentioning that the relative brightness is not directly related to the price category of the sight: models similar in this indicator can vary significantly in price.

Optical sights with parallax adjustment can be equipped with a wide ring on the AO (Adjustable Objective) lens or a drum on the SF (Side Focusing) control unit, on which additional accessories are installed for fine-tuning focusing in the form of wheels.

Units of measurement that are used in the marking of goniometric elements of the reticle. In our time, there are two main units: - MOA. The abbreviation for minute of arc is 1/60 of a degree. Initially, this unit is associated with the English system of measures and is convenient primarily for calculations in yards and inches: at a distance of 100 yards, an angle of 1 MOA corresponds to a linear dimension of approximately 1 inch. In the more familiar metric system for us, this gives 2.91 cm at a distance of 100 m. We also note that this unit is a kind of accuracy standard: it is believed that a full-fledged sniper rifle should give a spread of no more than 1 MOA.

— MRAD. Conventional designation miradian - an angle of one thousandth of a radian (approximately 0.06 °). Also in the jargon of snipers, this unit is called "thousandth", or "mil". It is already tied to the metric system: at a distance of 100 m, an angle of 1 MRAD corresponds to a linear size of 10 cm (approximately 3.5 times greater than 1 MOA).

The choice for this indicator largely depends on the personal preferences of the shooter. We also note that inconsistencies are often found in low-cost sights: their drums are marked on the MOA scale, and the reticle is in MRAD units.

The weapon class that this scope can be used with.

Different classes of weapons differ in the energy of the shot and, accordingly, the recoil force that the sight must endure without consequences. It is the maximum allowable energy of the shot (muzzle energy) that in this case is the main criterion for classifying the sight into one of the categories: light pneumatics, rifles and shotguns, large caliber. It is worth saying that such a division is somewhat arbitrary — see details in separate paragraphs; here is their detailed description:

— Lightweight pneumatics. Sights designed for weapons that practically do not give recoil — such as air PCP rifles, spring-piston “breaks” with muzzle energy up to 7.5 J, carbines chambered for Flaubert, as well as airsoft drives. Such models are definitely not suitable for firearms: they do not tolerate even the recoil from small-caliber rifles, not to mention more serious use. And even pneumatics have their limitations — in particular, powerful (more than 7.5 J) spring-piston models give significant returns with strong vibrations, and in pistols with the Blow-back system, noticeable concussions occur not because of the shot itself, but from -for the work of automation. So it is better to equip these types of weapons with more durable and reliable sights.

— Rifles and shotguns. Sights that can be used with...rifles of small and medium calibers, as well as smoothbore weapons (shotguns). They have a solid construction that allows them to endure rather strong recoil and accompanying vibrations without consequences, but the specific restriction on the allowable muzzle energy (and, accordingly, the calibers and ammunition used) may be different. However, scopes in this category are usually able to safely carry at least 2500 J — this is enough for rifled calibers 5.45x39, 7.62x39 and .223, as well as for 12-gauge rifle cartridges with a standard weight of gunpowder. And in many models, the maximum allowable energy can reach 3500 J and even 4000 J (the smallest values \u200b\u200bnecessary for full-fledged use with .308 and 7.62x54R calibers, respectively). At the same time, for reinforced magnum ammunition, as well as for some powerful (though not large) calibers, such a sight may still not be enough.

— Large-caliber. The most durable and reliable sights, designed for muzzle energy of 4000 J and above. Because of this, they can be used even with large-caliber firearms, as well as with some powerful calibers that are not formally large — for example, .300 Win and .338 Lapua Magnum. The specific restriction on muzzle energy, again, may be different, but if you are looking for a sight for a caliber more powerful than 7.62x54R or for reinforced rifle ammunition like 12x76, you should definitely pay attention to this category.

Separately, it is worth noting that “firearm” sights, even quite durable and reliable, are not recommended to be installed on pneumatics with a spring-piston mechanism or a gas spring. The fact is that such rifles have a specific recoil, directed forward rather than backward, moreover, giving sharp vibrations in different directions; and although the force of such recoil is low, it can still adversely affect the sight, which was not originally designed for it.