Home » Solitaire games » How coated optics work. Optics coating

How coated optics work. Optics coating

Effect: +25% to the viewing radius from a stationary tank.

Description

One of the most useful types of equipment. A 25% review bonus is very impressive and sometimes decisive. A tank or self-propelled gun that spots the enemy first has a huge tactical advantage.

As a rule, this is the right to the first shot or the opportunity for various maneuvers (change of position, retreat, turning to the enemy with armor).

Besides, good review beneficial in financial terms: if a tank sees further, then it is less likely to shoot at someone else’s light, on the contrary, it shines on its allies, thereby earning credits - as a result, all the income from its own shots and part of the income from the shots of allies goes into the piggy bank.

The stereo tube only works in a stationary position, so amateurs active play usually they prefer an alternative - coated optics.

However, in reality, even fast tanks can benefit enormously from the use of a stereo tube.

This can be a passive light for allies or a careful advance from cover to cover: when we reach a bush, we look around, if there is no danger, we move on.

Of course, the greatest benefit from the stereo scope will be felt by blind-sighted tank destroyers, such as Ferdinand, ISU-152, Jagdpanther and others. The pipe will allow them to detect the enemy at the limit of visibility first, shoot and reverse into cover to reload.

For blind vehicles with 260-330 field of view (Hetzer, SU-152, SAu-40 and others), the stereo tube can become a real lifesaver, especially at the end of the battle, when you need to drag.

Even with a stereo tube weak tank capable of fighting off several enemies coming under fire one at a time, or directing friendly artillery fire at them.

The pipe should not be used on close combat tanks such as Maus, E-100, IS-7, KV-5 and others. In addition, on equipment with a field of view of 390+, the effect of the pipe will be excessive at a visibility limit of 445 meters.

Of course, in this case the tank receives a bonus to uncloaking enemies, but it is still more rational to use optics on such vehicles.

Verdict

The stereo tube is of little use on howitzer self-propelled guns and close combat vehicles. For combat vehicles with a field of view of 390 and more, it is more rational to use coated optics.

For all others, this type of equipment is recommended for use. For most ambush snipers and tactical enthusiasts passive light must be installed.

Reduce (or completely eliminate) unwanted reflections.

Coated lenses usually require careful handling, since the thinnest coated films on the lenses are easily damaged. Films of contamination on the surface of the antireflective coating (grease, oil) disrupt its operating conditions and reduce its effectiveness, increasing the reflection and scattering of light. In addition, dirt (including fingerprints) can lead to erosion of the antireflective coating over time. Modern AR coatings usually have a protective outer layer, which makes them more resistant to environmental influences.

Antireflective coatings differ:

by number of layers;
application methods: etching, deposition from solution, sputtering in vacuum units...;
composition: usually these are salts and oxides of various chemical elements.

Historically, the first method was etching, in which a film of silica was formed on the surface of the glass.

Encyclopedic YouTube

1 / 5
Coating of optics (or anti-reflective coating) is used in many applications where light passes through an optical element and there is a need to reduce intensity loss or eliminate reflection. The most common cases are eyeglass lenses and camera lenses.

Corrective lenses

Anti-reflective coating is applied to glasses lenses because the absence of glare improves appearance and reduces eye strain. The latter is especially noticeable when driving a car in the dark and when working at a computer. In addition, more light passing through the lens improves visual acuity. Anti-reflective lens coatings are often combined with other types of coatings, such as those that protect against water or grease.

Cameras

Photo and video cameras are equipped with coated lenses. Due to this, the light transmission of the optical system increases and the image contrast increases due to glare suppression, however, unlike glasses, the lens consists of several lenses.

Photolithography

Anti-reflective coatings are often used in photolithography to improve image quality by eliminating reflections from the substrate surface. The coating can be applied either under or over the photoresist and can reduce standing waves, interference in thin films, and specular reflection.

Single layer coating

The thickness of a single antireflection layer (for example, silicic acid) must be equal to or a multiple of 1/4 of the light wavelength. In this case, the rays reflected from its outer and inner sides will be reflected in antiphase and, with equal amplitude, will be extinguished due to interference - the glare intensity will become zero.
For the best effect (equalizing the amplitudes of reflected light), the refractive index of the antireflective film should be equal to the square root of the refractive index of the optical glass of the lens. The traditional material for antireflection film is magnesium fluoride, which has a low (n = 1 , 38) (\displaystyle (n=1_(,)38)) refractive index. On refractive index crown glass, a layer of magnesium fluoride can reduce the percentage of reflection from about 4% to 2%. On heavier Flint glass with a refractive index of about 1.9, a film of magnesium fluoride can reduce the reflection to zero.
In the case where the wavelength is comparable to the texture size, reflection can only be calculated by numerically solving Maxwell's equations.
The anti-reflection properties of textured coatings have been well studied in the literature over a wide range of wavelengths.

Every World of Tanks player must remember that the strengths of a tank can and should be strengthened. Weaknesses, accordingly, must be eradicated. It is possible to achieve technical balance in a vehicle with the help of the crew (its skills and abilities), equipment and gear..
The reserve pocket does not fit
After purchasing the first tanks of levels 2-3, purchase equipment. At least it's removable. It includes: a camouflage net, a stereo tube and a toolbox. They are transferred from equipment to equipment without the need for dismantling, paid for in gold. Therefore, you should not buy a dozen camouflage nets or stereo tube. A couple of copies are enough.
Camouflage network(MS) reduces the visibility of a stationary vehicle. The action is activated 3 seconds after stopping. MC adds: 15% stealth for anti-tank self-propelled guns; 10% for light tanks (LT) and medium tanks; 5% for artillery and heavy tanks. The MS is useful for covert and positional combat, inherent in tank destroyers, as well as passive reconnaissance of armored vehicles. The mass of the MS is 100 kg, and the price is 100,000 credits.
Stereoscopic telescope adds 25% to the view from a stationary vehicle (no more than 445 meters). It allows you to detect the enemy before he detects you. Having the first shot is an important advantage in the game. The stereo tube, like the MC, is suitable for playing tank destroyers or tank destroyers. It is also good because it compensates for the shortcoming of many tanks - a low viewing radius. It's a pity, the properties of this useful item do not stack with coated optics. The mass of the stereo tube is 50 kg, the price is 500,000 credits.
Toolbox increases damage repair speed by 25%. Often it is installed while the crew’s repair skills are being upgraded, and then removed. The weight of the box is considerable - 100 kg, and the cost is even more so - 500,000.
Complex equipment
It can be removed from the car for only 10 units game gold or after destruction. For this reason, experienced tankers keep a handful of gold in reserve. In the name of savings, carefully consider the need for a particular module on your favorite tank. It's not rubber.
Springs are divided into many types as listed in the Wot Wiki. Their main tasks are to increase the load-carrying capacity of the chassis and mitigate damage when falling, so springs are useful in two cases. Firstly, they allow you to install a (heavier) cannon or turret if you lack the experience to research the chassis. Secondly, they insure a light and fast tank from severe damage when falling from hills and elevations. The cost of springs varies from 20,000 to 600,000 credits. Not to say that this is the most useful equipment in World of Tanks, but sometimes it makes sense to install them on a temporary basis.
Anti-fragmentation lining- another type of equipment that is not particularly popular. It increases the tank's protection against high-explosive artillery shells and reduces the risk of concussion of crew members by 20/25/30/50%, depending on the type of lining. The cost ranges from 50,000 to 750,000. It is reasonable to buy such a thing only for massive vehicles that often suffer from intense artillery fire. However, save space for more useful accessories.
Improved ventilation(Class 1-3) adds 5% to all crew skills. An excellent choice for those who want to gain an advantage in battle. The equipment is not available only for machines with an open cabin. The cost varies from 50,000 to 600,000 credits, and the weight is 100/150/200 kilograms. Improved ventilation should be installed on any tank, regardless of play style. For what? Because reloading is faster, visibility is better, and movements are more maneuverable. In combination with the "Combat Brotherhood" skill, commander bonus and premium equipment, you can increase the standard characteristics of the vehicle by 32%.
Wet ammunition rack adds 50% strength to... ammo rack. It's simple. This is not the most necessary equipment in the game, but in isolated cases it can help.
Rammer There are howitzer and gun, being divided into medium and large calibers. It reduces the gun reload time by 10%. It’s a pity that drum-loading tanks won’t have a useful device. Exceptions are: 59-16, Type 5 Chi-Ri and Spahpanzer SP I C. And because these vehicles have an alternative gun with a standard reload. The cost of the rammer varies from 200,000 to 600,000 credits and you shouldn’t skimp on them. Faster reloading - more shots - higher amount of damage - greater contribution to victory.
Additional lugs in most cases a waste of 250,000 credits. One of the most useless and rarely used types of equipment. Increases cross-country ability on soft and medium soils, but has strict restrictions on types of equipment. Grousers are installed on only 12 vehicles, and then mostly German ones. Use the Off-Road King driver skill instead.
Filling CO2 tanks adds 50% strength to tanks, reducing the risk of fire by the same amount. Becomes available from technology level VI. The equipment shares “honorable” place due to its uselessness with lugs and the “Cyclone” filter. It is useful for those whose tank burns in every battle like a witch at the stake of the Inquisition. The rest are recommended to use the “Cleanliness and Order” skill.
Coated optics- a very useful item that adds 10% to the viewing radius and works in motion, unlike a stereo tube. It is possible to install optics on any tank. Blind cars need it for obvious reasons. “Zorkim” will elevate the ability to detect the enemy to the absolute level. Typically, optics are installed on medium and light tanks, whose task is to search for the enemy. It costs 500,000 credits.
Vertical stabilizer Fits light, medium and heavy tanks VIII-X levels, as well as in some cars of a lower rank. The module reduces the dispersion of the gun when moving and turning the turret, i.e. Increases accuracy on the move. It costs from 500,000 to 600,000 credits. Its purchase is strictly recommended for fans of Soviet and American ST or TT.
Reinforced aiming drives- a necessary thing for any tanker. Unfortunately, most guns are slow to engage, and drives reduce this disadvantage by 10%. For some cars, this equipment turns from a panacea into a dope, increasing the already fast reduction to indecent speeds. It’s not worth half a kingdom, but it’s definitely worth half a million.
Filter "Cyclone" increases engine durability by 50% with a limit of soviet tanks and is infinitely far from the status of “Best Seller”. So he’s not worth his 500,000 credits.
Summing up and distributing advice
Not all equipment is equally useful or effective. The most important thing for the player is to choose the ideal kit for a specific car, revealing its full potential. Let’s take, for example, an “American” of level X without obvious disadvantages - T110E5. Good stabilization of the gun is complemented by a vertical stabilizer. Fast reloading is accelerated by the gun rammer. Crew skills increase after installing improved ventilation. As a result, the T110E5 becomes even more accurate, faster and more dangerous for the enemy. The Soviet Tier VIII heavyweight IS-3, on the contrary, has disadvantages. However, the slow aiming of the gun is offset by aiming drives, poor shooting on the move by a stabilizer, and slow reloading by a large-caliber rammer.
Final advice: Do not spend a huge amount of credits on purchasing modules, but try to wait for holiday promotions from Wargaming. Discounts on equipment will allow you to replenish your own warehouse, saving significantly on purchases.

Coating of optics is the application of the thinnest film or several films one on top of the other to the surface of lenses bordering on air. This is necessary to increase the light transmission of the optical system. The refractive index of such films is less than the refractive index of lens glass.
Antireflection films reduce light scattering and reflection of incident light from the surface of the optical element, accordingly improving the light transmission of the system and the contrast of the optical image. A coated lens requires careful handling, since the films applied to the surface of the lenses are easily damaged. In addition, the thinnest films of contaminants (grease, oil) on the surface of the antireflective coating disrupt its operation and sharply increase the reflection of light from the contaminated surface. It should be remembered that fingerprints over time destroy not only the coating, but also the surface of the glass itself. According to the application method and composition of the antireflective coating, antireflection can be physical (spraying) or chemical (etching).
Single layer coating
(Interference in quarter-wave anti-glare coating)
The thickness of the antireflective layer (for example, silicic acid) equals 1/4 light wavelength. In this case, the rays reflected from its outer and inner sides, will be extinguished due to interference and their intensity will become zero. For best effect refractive index of the antireflective film should be equal to the square root of the refractive index of the optical glass of the lens. The most suitable material for antireflective film is barium fluoride, with very low (n=1.38) refractive index. However, barium fluoride is soluble in water and requires a protective coating.
The reflectivity of glass coated in this way strongly depends on the wavelength, which is the main disadvantage of single-layer coating. The minimum reflectivity corresponds to the wavelength λ = 4d n, where d is the thickness of the film, n is its refractive index. In the first coated lenses, they achieved a decrease in the reflectance coefficient for rays of the green part of the spectrum (555 nm- the area of greatest sensitivity of the human eye), therefore, in reflection, the glass of such lenses had a blue-violet or bluish-green color (“blue optics”). On the contrary, the transmission of light by such a lens is maximum at this wavelength, which led to noticeable coloration of the image.
Currently, single-layer coating is often used for laser optics designed to operate in a narrow spectral range. By using glasses with a relatively high refractive index and sputtering a film of barium fluoride, it is possible to achieve a minimum reflectivity of about 1%. The main advantage of such enlightenment is its low cost.
Multilayer coating
(Multi-coated lens)
A multilayer antireflective coating is a sequence of alternating layers (their number reaches 15 or more) of two (or more) materials with different refractive indices. Multilayer antireflective coatings are characterized by low reflection losses (narrowband coatings for laser optics with a reflectivity of about 0.3% or less, broadband coatings - up to 0.5%). The main advantage of multilayer coating in relation to photographic and observational optics is the insignificant dependence of reflectivity on wavelength within the visible spectrum (on the graph of reflectivity versus wavelength, two or more minima are observed, separated by small maxima, and outside the working band there is a strong increase in reflectivity ), which significantly reduces color distortion. Reflections from the surface of lenses with multilayer coating, depending on the quality, have various shades of green and violet, up to very weak gray-greenish in lenses of recent years of production. Optics with multilayer coating were previously marked with the letters MC (for example, MS Mir-47M 2.5/20). Nowadays, the special designation of multi-coating is rare, since its use has become a standard. Sometimes there are “branded” designations for its special varieties: SMC (Pentax), Super Integrated Coating, Nano (Nikon) and others. The composition of a multilayer antireflective coating, in addition to the antireflection layers themselves, usually includes auxiliary layers - improving adhesion to glass, protective, hydrophobic, etc.

A coated lens requires careful handling, since the films applied to the surface of the lenses are easily damaged. In addition, the thinnest films of contaminants (grease, oil) on the surface of the antireflective coating disrupt its operation and sharply increase the reflection of light from the contaminated surface. It should be remembered that fingerprints over time destroy not only the coating, but also the surface of the glass itself. According to the application method and composition of the antireflective coating, antireflection can be physical (spraying) or chemical (etching).

Single layer coating

The thickness of the antireflection layer (for example, silicic acid) is equal to 1/4 of the light wavelength. In this case, the rays reflected from its outer and inner sides will be extinguished due to interference and their intensity will become zero. For the best effect, the refractive index of the antireflective film should be equal to the square root of the refractive index of the optical glass of the lens. The most suitable material for antireflection film is barium fluoride, which has a very low (n=1.38) refractive index. However, barium fluoride is soluble in water and requires a protective coating.

The reflectivity of glass coated in this way strongly depends on the wavelength, which is the main disadvantage of single-layer coating. The minimum reflectivity corresponds to the wavelength λ = 4d n, where d is the thickness of the film, n is its refractive index. In the first coated lenses, they achieved a decrease in the reflectivity for rays of the green part of the spectrum (555 nm is the region of greatest sensitivity of the human eye), therefore, reflection, the glass of such lenses had a blue-violet or bluish-green color (“blue optics”). On the contrary, the transmission of light by such a lens is maximum at this wavelength, which led to noticeable coloration of the image.

Currently, single-layer coating is often used for laser optics designed to operate in a narrow spectral range. By using glasses with a relatively high refractive index and sputtering a film of barium fluoride, it is possible to achieve a minimum reflectivity of about 1%. The main advantage of such enlightenment is its low cost.

Multilayer coating

Multi-coated lens

A multilayer antireflective coating is a sequence of alternating layers (their number reaches 15 or more) of two (or more) materials with different refractive indices. Multilayer antireflective coatings are characterized by low reflection losses (narrowband coatings for laser optics with a reflectivity of about 0.3% or less, broadband coatings - up to 0.5%). The main advantage of multilayer coating in relation to photographic and observational optics is the insignificant dependence of reflectivity on wavelength within the visible spectrum (on the graph of reflectivity versus wavelength, two or more minima are observed, separated by small maxima, and beyond working strip there is a strong increase in reflectivity), which significantly reduces color distortion. Reflections from the surface of lenses with multilayer coating, depending on the quality, have various shades of green and violet, up to very weak gray-greenish in lenses of recent years of production. Optics with multilayer coating were previously marked with the letters MS (for example, MS Mir-47M 2.5/20). Nowadays, the special designation of multi-coating is rare, since its use has become a standard. Sometimes there are “branded” designations for its special varieties: SMC (Pentax), Super Integrated Coating, Nano (Nikon) and others. The composition of a multilayer antireflective coating, in addition to the antireflection layers themselves, usually includes auxiliary layers - improving adhesion to glass, protective, hydrophobic, etc.

Infrared optics

Some optical materials used in the infrared range have a very high refractive index. For example, germanium has a refractive index close to 4.1. Such materials require mandatory clarification.

Textured coatings

Reflection can be reduced by texturing the surface, that is, creating an array of cone-shaped diffusers or two-dimensional grooves on it. This method was first discovered when studying the structure of the eyes of some species of moths. The outer surface of the cornea of the eye of such moths, which plays the role of a lens, is covered with a network of cone-shaped pimples called corneal nipples, usually no more than 300 nm in height and approximately the same distance between them. Since the wavelength of visible light is larger than the size of the pimples, their optical properties can be described using the effective medium approximation. According to this approximation, light propagates through them in the same way as if it propagated through a medium with a continuously varying effective dielectric constant. This in turn leads to a decrease in reflectivity, which allows the moths to see well in the dark and also remain undetected by predators due to the decrease in reflectivity from the eyes.

A textured surface also has anti-reflective properties in the short-wave limit, at wavelengths much shorter than the characteristic size of the texture. This is due to the fact that rays initially reflected from a textured surface still have a chance to penetrate the medium during subsequent re-reflections. In this case, surface texturing creates conditions under which the transmitted beam can deviate from the normal, which leads to the effect of entangling transmitted light (English - light trapping), used, for example, in solar cells.

In the long-wavelength limit (wavelengths greater than the texture size), the effective medium approximation can be used to calculate reflection. In the short wavelength limit (wavelengths smaller than the texture size), the ray tracing method can be used to calculate reflection. In the case where the wavelength is comparable to the texture size, reflection can only be calculated by numerically solving Maxwell's equations. The anti-reflection properties of textured coatings have been well studied in the literature over a wide range of wavelengths. .

See also

Sources

Literature

Yashtold-Govorko V. A. Photography and processing. Photography, formulas, terms, recipes. Ed. 4th, abbr. M., “Iskusstvo”, 1977.

Wikimedia Foundation. 2010.

See what “Optics enlightenment” is in other dictionaries: