Comparison Nikon ProStaff 3-9x50 vs Leupold VX-2 3-9x50

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 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.

The scope has a zero adjustment function. This function is used during the initial sighting of optical sights (see "Type") for a specific rifle and ammunition, and later it greatly simplifies the work with vertical and horizontal corrections. Its essence is as follows

The process of zeroing in optics, roughly speaking, is the selection of such a position of the drums, in which at a distance of 100 m the sight ensures a clear hit at the aiming point (taking into account the spread of the weapon, of course). Such settings are taken as zero, it is from them that all further corrections are counted. However, the scales of the drums already show certain values by the time they are brought to this position — because of this, when you subsequently enter corrections, you can get confused in the number of clicks, make a mistake when returning the sight to its original settings, etc. The zero setting solves the problem: after zeroing, it is possible to rearrange the scales of the drums to the zero position without knocking down the settings of the adjusted sight. Thus, all subsequent corrections of the hands will be able to count from zero values on the scale, and to return to the original settings, it is enough to return the drums to the same zeros.

The specific method and features of such a setting may be different, usually, they are described in detail in the instruction manual. Here we note that this function is highly desir...able for sights used in high-precision (sniper) shooting, where you have to work a lot and often with amendments.

A type of coating used in scope lenses. Anyway, we are talking about the so-called antireflection coating, which is the thinnest film (single or multilayer) on the surface of the lens in contact with air. The properties of this film are chosen in such a way as to minimize the reflection of light from the glass surface. The meaning of this function is not so much to reduce the brightness of glare that can unmask the shooter, but to increase the light transmission of the optics and, accordingly, the quality of the image visible through it.

Modern sights can be equipped with the following types of coatings:

— Illuminating. In this case, the simplest option is implied — an incomplete single-layer coating. The term "incomplete" means that not all lens surfaces are coated (although there may be several coated surfaces). Such enlightenment is inexpensive, however, the image quality is relatively low — in particular, because a single-layer film is most effective only for a part of the visible colour spectrum.

— Full illumination. Fully coated means that all surfaces of the lenses that come into contact with air have a special coating; in this case it is single layer. Such a coating is more expensive than a simple anti-reflective coating, but the quality of the “picture” when using it is higher, because. light distortion at the transitions between glass and air is minimized.

— Multi-layered illuminating. Incomplete AR coating (see above)...using multilayer films. Thanks to multiple layers, the anti-reflective coating covers the entire visible spectrum, which allows you to achieve a brighter image with less colour distortion compared to single-layer coatings; However the price of such devices is higher.

— Full multilayer enlightenment. The most advanced option: multilayer coating on all lens surfaces used in the design of the sight. Features of full and multi-layer coating are described separately above. Here we note that their combination is typical for high-class sights, because. it provides the highest quality image, but it is not cheap.

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").

The country of origin of the brand under which the product is sold. Nowadays, the sights market is mainly represented by brands from such countries (in alphabetical order): Belarus, Great Britain, Germany, Spain, Lithuania, USA, Japan. However, there are other options as well.

There are many stereotypes about how the origin of a particular country affects the quality; however, nowadays, they have practically no basis. First, the origin of the brand is indicated either by the actual place of origin of the company, or by the country in which its headquarters is located; in both cases, this country does not always coincide with the country where the production is located and where the device was actually manufactured. For example, it is quite normal for the products of an American or German brand to be manufactured in Taiwan or Turkey. Secondly, the actual quality of a product is primarily affected by how it is positioned in the market and how carefully the manufacturer ensures quality control. As a result, paying attention to the "homeland" of the brand makes sense only when you fundamentally want or do not want to support a company from a certain country; in other cases, it is worth focus primarily on the reputation of a particular...manufacturer.

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.