The inability of the human eye to see well in low-light conditions has been a problem for a very long time. Only in the 40s of the last century did this issue resolve, and night vision technologies began to develop. From their creation to the present day, these devices have undergone various changes in appearance, functionality, purpose, or principle of operation.
Therefore, for example, in the military or hunting, users are comfortable using a scope that contains an electronic, optical converter (EOC) used for observation in the infrared and ultraviolet range, which allows amplifying the light invisible to the human eye to the image visible through the eyepiece of the device. Its noticeable difference from a night vision monocular is that it can be mounted on firearms, airguns, and, if necessary, crossbows.
However, night vision scopes are being improved yearly, with new models coming out regularly. And this makes it very difficult for beginners to choose. When you go to a website or store for hunting, you risk leaving them empty-handed because your attention is scattered, and you need to know what criteria you need to pay attention to first when choosing such optics. Therefore, before looking at specific options for night vision sights, you need to study the main criteria that you will subsequently pay attention to in more detail.
An analog night vision device, i.e., one with an electronic-optical converter in its design, can be Gen1, Gen2, Gen3, or Gen4. The EOC multiplies the light that determines the generation and image quality of the night vision device.
The First-Generation Technology
The first-generation technology was based on photomultipliers placed between the photocathode and the eyepiece, which allowed for multiple amplification of visible and IR light, with the latter being converted to the visible range. It is still in use today because of its low price and minimal yet essential functions.
A characteristic and widely known feature of this type of night sight is that the image is evident only in the center, and distortion and lower resolution are observed at the edges. In shallow light conditions, there is a need for additional infrared illumination for the night vision device. To increase the gain, sometimes two or three, or more products are constructively combined into one housing.
At the same time, it is necessary to avoid bright light sources, which also have an unpleasant effect on the functionality of the optics, as the image will be illuminated, which will become a serious obstacle to your observation, especially for an accurate shot.
Devices of this generation can be significant in size and weight. Cheaper materials are used to create them. However, these criteria affect its price. Despite issues that may arise when working with such a sight, it may be worthwhile for beginners to start their acquaintance with such optics with first-generation models to understand the principle of operation and what to compare it with.
The Second-Generation Technology
Second-generation sights are usually in demand among law enforcement officers. They are a bit more expensive than the models of the segment mentioned earlier, which is quite logical due to the use of a new part in the design, namely a microchannel plate (MCP). The MCP works like an electronic amplifier, is placed directly behind the photocathode, and consists of millions of short parallel glass tubes. As electrons pass through these short tubes, thousands more electrons are released.
This allows 2nd generation devices to amplify light much more than 1st generation devices, providing brighter and clearer images in low-light conditions such as moonlight or starry skies. The excellent capabilities of Generation II CCDs are due to high-power lenses (1.5:2; 1:2), which are three- or fivefold magnified. As a result, this makes it possible to work with such a sight at night, even without moonlight. It is generally possible to detect a human figure from about 400-600 meters and, in detail – from 250-300 meters.
The Thrid-Generation Technology
Gen3 is a standard for the U.S. military. Adding the sensitive chemical gallium arsenide to the photocathode produces a brighter and clearer image than Gen2 devices. An ion-barrier film was added to increase the life of the tube.
The third-generation night vision sight gives the user excellent performance in low light. Another noticeable advantage that needs to be noticed is the clarity and saturation of the picture, high contrast. All the details are rendered quite well. But there is a slight drawback – there is no protection from side light sources due to the absence of an optical fiber washer at the entrance. This feature makes it unsuitable for use in the city, for example.
The cost of the device increases at least twice. This emphasizes its advantages, which include high-tech developments and compactness, which is an important criterion when choosing a sight to avoid adding weight to the rifle.
The Gated/Filmless Gen4 technology, by removing the ion-barrier film and “strobing,” demonstrates a significant increase in target detection range and resolution, especially in external light conditions.
The filmless micro channel plate provides a higher signal-to-noise ratio than standard 3rd generation IITs, which ensures better image quality in low light conditions. Automatic/filmless inverting EOFs increase nighttime performance for users of night vision scopes.
The auto-gating power supply further improves image resolution in high-light states and reduces the halo effect, minimizing interference from bright light sources. The reduced halo maximizes the effectiveness of the night vision device in dynamic lighting conditions, such as those encountered in nighttime operations in urban areas.
The principle of operation of night vision devices is the same regardless of their type. The device accumulates all the reflected light (in a minimal amount), amplifies it with a unique converter, and delivers the resulting monochrome image to the user’s eyes. Due to the human eye’s enhanced sensitivity to the colors of the green spectrum, the painting acquires greenish tints.
The sights’ capabilities are enhanced by infrared radiation, which the human eye cannot see because it operates at an ultra-high frequency. However, this feature significantly improves the image quality as result. Consider the following criteria when purchasing a scope you intend to use in the dark.
The larger it is, the more influential the focal power of the instrument. That is, devices with a large lens give a clearer picture.
Viewing range – the distance from the device to the inspection object with the most precise possible image. Zoom is a multiple magnification of the picture. It would be best to consider this a digital zoom, meaning each additional zoom degrades the image quality.
The extensive zoom range is beneficial because of the way night vision scopes work.
Night vision scopes often have a fixed optical zoom of 3x, 4x, or 5x. Thanks to digital zooming, some night scopes sometimes reach 20x – 25x for even greater distance accuracy.
Viewing angle measured in degrees. Linear dimensions and weight – The instrument must be tiny and lightweight for combat use. Resolution – the clarity of small elements within a given focus range.
Price and features
No matter how much you want to have the maximum number of features a riflescope can have, you should always be critical and prudent in your choice. And it depends on the many questions you must ask yourself before making a purchase.
The first of them is the scope and purpose of use. It can be different. This is a military matter; you are a law enforcement officer, a hunter. This is what you will start from. For each area of use, there will be parameters that you will prefer.
Because it is not usual that where there is an advantage, there is a disadvantage in another function. For example, for hunting, you must pay attention to the shock resistance of the material from which the scope was made and the glass used for its construction. Hunting is an extreme hobby; reckless manipulation and optics will be damaged. Nevertheless, this advantage will affect its weight, which will be reflected in the position of your weapon.
Visibility and Functionality
Also, consider how extreme your work conditions with such a device will be. This will affect which generation you need to look at. For example, in some states, night hunting is prohibited. However, dusk falls quickly during the fall hunting season, and this illumination will be enough to make a shot and improve visibility at a time when the functionality and capabilities of a conventional scope will not be enough.
But it’s pointless to deny that this is precisely the situation when you need to spend thousands of dollars for a night vision scope of the most expensive segment.
Rechargeable batteries power night vision scopes to keep you visible without external light. Therefore, the battery life of your scope plays a significant role in how long you can continuously use it without having to replace the battery. Some of the best night vision scopes will have extraordinary battery life and allow you to use them longer in the field without worrying about them breaking down at the wrong time.
However, it would be best always to have spare batteries for the volume you choose, regardless of the lifespan. Nothing is worse than running out of battery while hunting! This can also affect the autonomy of your device.
Quality of Vision Scope
Like the quality of the glass, the durability of the night vision scope you choose will determine how long you can rely on it without replacing it. Some of the best models will be labeled “weatherproof,” which combines waterproof, fog proof, and shockproof. Waterproof riflescopes are usually an excellent choice in terms of value for money.
They are reliable, even if you take them out into the woods during inclement weather. In addition, it’s worth finding a night vision scope made of aircraft-grade aluminum or a similar durable material. Some excellent night vision scopes are advertised as anodized to increase the scope’s durability. However, this means that the body of the night vision scope is rust-resistant and unlikely to corrode. This coating will also reduce glare and help camouflage your position.
Some night vision scopes allow you to record videos or take photos. This can be useful for a variety of reasons. For example, you may want to remember a particularly valuable hunt you did a year ago. A video camera connected to the telescope allows you to record this moment. As for the format of the memory card, it is usually a microSD with a capacity of no more than 32 GB or 64 GB (depending on the model).
And these are the moments that, of course, influence how many thousands of dollars you will spend on this device to make your work easier.
First-Time Use of Night Vision Scope
The following rule can be used even before you have purchased a personal night vision scope. Take a training course at a specialized facility. This is an excellent opportunity to hold several variants in your hands, aim, understand the device’s specifics, see the possible functions, how to configure them, and what some similar parameters in many models mean. Such actions will clarify the choice of optics in the future. You should take the opportunity to consult with people who are more experienced in this area.
Before you use your riflescope, you should scrutinize it. Understand when it works, when it is off, what signals it is time to change the battery, how the zoom works, the reticle, etc. So it would be best to practice before you use it in your career.
So mainly remember the importance of practice and thorough preparation. Pay attention to the advice of experienced people on how to use the device. Make your choice carefully, do not be tempted by cool features if you do not need them.