Type
—
Optical. Classic optical sights; in essence, telescopes of a special design with sighting reticles applied in the field of view. It is precisely these “pipes” that are traditionally used for sniper shooting - both high-precision and “fast”, for example, in hunting (however,
“pipes” are placed in a separate category). They can have both a small and a very high degree of magnification (in many models this parameter is also adjustable), provide the ability to make adjustments vertically and horizontally, and the marking of many sighting reticles allows you to make such adjustments on the fly without reconfiguring the sight itself. But optics are not suitable for the fastest possible shooting offhand: aiming takes a lot of time, and the field of view is limited. In addition, using such a sight requires a certain skill - so, ideally, the shooter’s eye should be located on the optical axis (for more details, see “Parallax adjustments”) and at a strictly defined distance from the sight. Note that the sights themselves do not require batteries, but power may be required for some additional functions, such as illuminating the reticle. In the dark, the optics themselves are practically useless; only a few models are compatible with NVGs.
- “Penchor”. Closed-type optical sights, originally developed for driven hunting. Their characteristic feature is the ability to make quick shots offhand while maintainin
...g a large field of view for the shooter. Externally, the “drivers” are often compact, and the size of their lens is most often no larger than the “landing size of the rings.” Such sights are equipped with the ability to adjust the magnification (on average 1x – 4x, but the maximum magnification can be higher, but the minimum magnification is not more than 2x). The main task of the “driver” is to guide a rapidly moving target during daylight hours, both at a short distance and at a medium distance, firing with target recognition (aimed shooting is ensured at a distance of 5 - 150 m). They are often equipped with a backlight module, which at 1x magnification turns the sight into a collimator sight and allows you to quickly target an object near the shooter and not lose the aiming mark in the thicket of the forest when searching for a target.
— Collimator. Sights based on optical systems in which the aiming mark is not fixedly applied to the lens, but is projected onto it using a special light source. Despite the external similarity of some of these models with traditional optics, collimators have actually the opposite specialization: they are designed for short distances and the ability to quickly fire offhand. Thus, such devices usually do not provide magnification or narrow the field of view (there are exceptions, but they are extremely rare), and the aiming mark always more or less coincides with the actual aiming point, regardless of the position of the working eye relative to the sight. From the shooter's perspective, it looks like when the head moves, the mark also moves, remaining on the target. True, despite the common misconception, the collimator design itself does not guarantee the absence of parallax (see “Parallax adjustments”); however, when this effect is present, it is usually weakly expressed and has almost no effect on shooting accuracy, and there are also completely parallax-free models. The main disadvantage of collimator collimators is that they require battery or battery power.
- Prismatic. At its core, it is a compact hybrid of an optical and collimator sight. From classical “optics”, such sights borrowed a lens system that provides slight magnification, and an engraved aiming reticle etched on the prism glass itself. However, unlike traditional optical sights, they have a more compact prismatic wrapping system. Externally, prismatic-type models are similar to closed collimator sights. They also use reflective illumination of the reticle and provide an integrated mount, mainly for the Weaver rail. Most prismatic sights have the ability to change the reticle and select the illumination color (usually red or green). Sights of this type provide quick target acquisition, and they are designed for accurate shooting at short and medium distances.
— Magnifier. Optical devices installed in front of sights to increase the zoom ratio, thanks to which the shooter can see distant objects more clearly and aim at targets faster. Magnifers are mainly used in conjunction with collimator sights (see the corresponding paragraph). Their magnification ratio varies from 3x to 7x. Often such optical devices come with a special mount that allows you to instantly “throw” the magnifier to the side for aiming directly through the collimator.Magnification
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.Lens diameter
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.
Exit pupil diameter
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.
Twilight factor
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.
Brightness
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.
Adjustment division value
The division value of the turrets used in the sight to enter corrections.
The increment value for the correction turret is the angle that the point of impact shifts when rotated by 1 click (“click”). In this case, this angle is indicated in MOA — minutes of arc. For more information about this unit, see "Measuring units of the sight"; and the lower the division value, the more accurately you can set up the sight initially and make corrections in the future. For example, if this indicator is 0.5 MOA — each click will shift the point of impact by about 1.46 cm for every 100 m of distance (that is, 2.91 cm at a distance of 200 m, 4.4 cm at 300 m and so on); and 0.25 MOA will already give only 7.3 mm per click for every 100 m.
The smaller the step and the more accurate the adjustment system, the more expensive it is. Therefore, when choosing, it is worth taking into account the features of the planned application — first of all, the size of the targets and the distance to them; detailed recommendations on this matter are in various manuals on shooting. If we talk about specific values, then the mentioned 0.5 (1/2) MOA are typical mainly for inexpensive and medium scopes, 0.25 (1/4) MOA is a pretty good indicator, and the advanced optics itself allows adjustment in increments of 0.125 (1/8) MOA.
Reticle
The location of the reticle in the optical sight (see "Type").
Such a grid can be installed either in the
first focal plane, FFP(roughly speaking, in the lens area), or in the
second, SFP(in the eyepiece area). At the same time, for sights with a fixed magnification, the difference between these options is only in price, so they use only the simpler and cheaper SFP. But in models with multiplicity adjustment, this parameter directly affects the application features, and we will analyze this difference in more detail:
— In the 1st focal plane (FFP). The key advantage of reticles in the first focal plane is that their apparent size also changes in direct proportion with a change in magnification. In fact, this means that the angular dimensions of the individual mesh elements remain the same regardless of the set magnification. That is, for example, if a distance of 1 MRAD is claimed between two neighboring points, then it will be 1 MRAD in the entire range of multiplicity adjustment. This means that you can work with the grid for measuring distances and taking corrections according to the same rules, regardless of the selected degree of increase. Thus, FFP sights are much more convenient and easier to use than SFP. On the other hand, such models are noticeably more complex and expensive; and many hunting reticles — for example, a duplex or a classic cross (see "Reticle Type") — it makes
...no sense at all to install in the first focal plane. In light of all this, this option is relatively rare and only in mid-range and top-level models designed for high-precision shooting.
— In the 2nd focal plane (SFP). The most common reticle placement option, including variable magnification sights. Such popularity is primarily due to the simplicity of design and low cost. However, the reverse side of these advantages are additional difficulties when using goniometric mesh elements. The fact is that in SFP sights, the apparent size of such elements remains unchanged when the magnification changes, which means that the dimensions of individual parts at different magnifications will correspond to different angles. More precisely, the angular dimensions in such systems change in inverse proportion to the multiplicity: for example, if at a multiplicity of 5x the distance between two adjacent points is 6 MOA, then at 15x it will decrease to 2 MOA. Thus, the “true” angular size indicated in the characteristics, the marking elements have only at a strictly defined multiplicity, in other cases, this size must be recalculated using special formulas. At the same time, it is worth noting that if the grid does not have special goniometric elements, then this disadvantage becomes practically irrelevant for it; examples are hunting nets of the "half-cross" type (traditional, not "stump") and "cross with a circle" (see "Net type").Reticle type
The type of aiming mark (reticle) provided in the device. There are models for which several options are indicated at once: this implies the possibility of switching between them.
As for specific varieties, in collimators, all brands have a common specificity - they should provide the convenience of quick aiming at relatively short distances. But the reticles of optical and other similar sights can be divided into hunting and tactical (sniper) sights. The former are relatively simple and have a minimum of additional elements, as they are designed for short distances and relatively large targets; and the latter are designed for high-precision shooting, military and police use, and therefore must be supplemented with various elements for measuring angles and taking corrections on the go, including between shots.
Among the specific types of grids most popular in our time are
the cross with divisions,
BDC,
duplex,
cross,
half-cross,
cross with a dot,
cross with a circle,
herringbone,
rangefinder,
dot,
circle with a dot and
circle with 2 points. Here are th
...e main features of each:
— Cross with divisions. One of the most popular types of "tactical" reticles used in optical sights. The key element is the crosshair, on the lines of which additional dots are applied. The distance between the points corresponds to a strictly defined angular size; initially it was 1 MRAD (1 "mil", hence the name), however, in modern sights, other values \u200b\u200bcan be found, they should be specified according to the instructions. In addition, such grids can differ in the number of points, the presence of thickening on the lines (as in the duplexes described below), etc. Be that as it may, such a grid is very convenient for estimating distances and making corrections on the fly, many professional shooters consider it almost ideal for high-precision shooting, including at long distances, besides, the original cross with divisions (Mil-Dot) is widely used by military and police snipers around the world.
We also note that there is also a collimator variety of "mildots" - in this case, the grid looks like a circle with a dot in the middle and several dots below it, with an interval of the same 1 MRAD. However, when using collimators, the real need for making vertical corrections rarely arises, and this option is not widely used.
- Duplex. Reticles for optical and night sights (see "Type"), which look like a classic crosshair with different line thicknesses: they are thin in the center, and noticeably thicker near the edges. The meaning of this combination is that thin lines do not “clutter up” the field of view at the aiming point, and thick lines remain visible even under adverse conditions (for example, at dusk) and allow you to aim at least approximately. In addition, the thickness of large lines and the distance between their edges can correspond to well-defined angles, which allows some of these sights to be used even as simple goniometers. However, these possibilities are very limited, and in general, "duplexes" are classic hunting nets.
- Half cross. Hunting net, the main elements of which are T-shaped. One of the varieties of semi-crosses - "German grid", it is also "stump" - consists of a vertical line from the edge to the center of the sight and two horizontal lines that do not reach it; the aiming point corresponds to the upper point of the central "stump", and the thickness of the lines and the distance between them can be specified in the documentation - this allows you to carry out the simplest measurements of angles. A more modern version of the half-cross is the crosshair, in which one line (from the center to the top edge) is much thinner than the rest, or even absent altogether.
- Dot. In its pure form, the dot is used exclusively in collimator sights (see "Type"). This is an extremely convenient option for such devices: there are no unnecessary details in the field of view of the shooter, only a mark that clearly shows exactly where the weapon is aimed - more is often not required when using collimators. The disadvantages of the dot in comparison with other marks in the sights of this type include less visibility, especially in bright ambient light. However, many sights allow you to set a fairly high brightness of the mark, and sometimes even increase its size, increasing visibility. Also note that for a point, the angular size can be specified, which can be useful for quick estimation of distances.
In addition, the dot can also be used in optical and night sights, but in such cases it is usually used as an addition to another scale - for example, it additionally highlights the intersection of lines in a semi-cross.
— Circle with a dot. Another type of marks, used in collimators as the main one, and in other types of sights - as an addition to a crosshair or other more traditional grid. However, the latter is rare, so let's focus on the first option. Compared to another popular "collimator" mark - a dot - the circle covers more visible space, however, it is very noticeable and often turns out to be more convenient when shooting offhand or sharply turning the weapon to the side. In addition, for both the circle and the dot, it often indicates the exact angular size, which gives extended (compared to the usual dot) possibilities for using the aiming mark as the simplest goniometric (rangefinding) scale.
- Circle with 2 dots. A variation of the circle with a point described on top, having a second, additional point - usually below the first, at a strictly defined angular distance from it. This expands the possibilities for using the sight as an impromptu rangefinder, and also allows you to "on the move" take an amendment when shooting at long distances - just aim at the second, lower point. However, such opportunities for collimators are extremely rarely required, so this option has not received much distribution either.
- Cross. Features of this type of brand depend on the type of sights in question - optical / night or collimator (see "Type"). In classical optics, a cross is the simplest crosshair of thin lines of the same thickness. Naturally, in terms of general specialization, such reticles are hunting, but they are also found in a fairly advanced variety of sights - sports models for benchrest (shooting from a machine gun at maximum range and accuracy). The convenience of the cross in such an application lies in the fact that the lines have a minimum thickness and practically do not block the view. In nightlights, this type of grid is usually one of several options available to choose from. But in collimators, the cross is in many ways similar to a circle with a dot - it is provided as one of the large, well-marked marks with a clearly defined angular size.
- Cross with a dot. A grid in the form of a crosshair of two lines (as a rule, quite thin), at the intersection of which a clearly visible point is applied. It is in this form, as a rule, that is used in collimator and other types of sights. In the first case, such a stamp is actually a slightly modified version of the usual cross (see on top). And in optics, the presence of a point allows you to additionally highlight the crosshairs, which is convenient in some situations; the general purpose of such sights is, of course, hunting.
- A cross with a circle. Stamp in the form of a cross, complemented by a circle. It can also be used in different types of sights and has its own specialization everywhere. In classical optics, such a grid usually has a hunting purpose, although there are also varieties with additional marks that expand the "tactical" functions. And even in the absence of such marks in the characteristics, the angular size of the circle is usually specified, which provides additional opportunities for impromptu measurement of distances. We also note that the cross itself can be both ordinary and duplex (see on top). The situation is similar in night sights, however, there a cross with a circle is usually only one of the available mark options. As for the collimators, they can use both a full-fledged crosshair in a circle, and a ring with “rays” protruding from it; in any case, such a mark is more noticeable than an ordinary cross.
— BDC. This reticle got its name from the English phrase Bullet Drop Compensation, which translates as “bullet drop compensation”. The BDC ballistic reticle allows for range correction based on the bullet's trajectory. It is calibrated for a specific ammunition and sharpened for quick aiming at various distances using the same type of bullets. Distance markers in a ballistic reticle are hash marks, circles, or dots. The main sign of their placement is that the vertical markings have different gaps, increasing towards the bottom. An additional distance scale is often placed in such grids on the "six" shoulder. In addition, the ammunition for which the reticle is calibrated is usually indicated (caliber, bullet weight, weight).
- Christmas tree. Informative reticle resembling a Christmas tree in its structure. Actually, this is where the name of this type of grid came from. Each array of dots on its "six o'clock" arm is longer than the previous one - the marks increase in width when viewed from top to bottom from the central crosshair. These markers are used to correct for wind drift, which is extremely important when conducting aimed fire at long distances. The most common herringbone reticle is found in hunting hybrids, tactical sights, and military rifle scopes.
- Rangefinder. This type includes all grids that do not belong to any of the types described on top and provide for special markings for measuring angles and distances. The specific design of such markings may be different, but the general principle of operation is the same everywhere: rangefinder marks allow you to determine the angular size of a visible object, and if the linear size of this object is known, you can easily estimate the distance to it (at least approximately). Each type of rangefinder reticle has its own rules for use.