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Night vision scope is a cool device for hunters and shooters. When you want to aim at targets at night, there is no other alternative like a night vision scope for rifles.
Newbie hunters or shooters even veterans should consider several things before buying any NV scope. If you are one of them who is looking for a good scope, then this article will help you a lot to understand the fact rightly. So, let’s get started.
Night vision scope (NVS) is a night viewing device that works through some fundamental optical principles. This device produces infrared (IR) light into visible light or near-visible light. In this way, we get a green (most of the cases) or red image of the objects. Awesome, right?
Each unit consists of several basic components such as an image intensifier tube, water-resistant housing, protective lens, mounting system, etc. NV scopes were primarily designed for military and law enforcement tasks. However, recently now they are being used for civilian purposes also.
Good night vision scopes are available with three different technologies i.e. active illumination, image intensification, and thermal imaging.
Image enhancement converts energy through complicated processes. This occurs in a vacuum tube or intensifier tube. Image intensifier converts low light photons into electrons. The process continues until electrons convert into light photons.
Natural sources like the moon, stars emit lights that enter into the intensifier tube as photons of light. The light hits the objective lens and photocathode. Later on, these lights strike the microchannel plate (MCP). Finally, the phosphor screen receives the accelerated electrons and we see the green lights through the eyepiece.
You may know about digital night vision devices or low light cameras, which use active illumination technology. When image intensification receives lights from active sources in the shortwave or near-infrared band, this is called active illumination. Usually, the infrared spectral range differs from 700 to 1000 nm.
Active illuminator produces high-quality images and removes shadows from the output. This makes it possible to see through fog, snow, or smoke.
Thermal imaging is another wonderful night vision technology that detects heat energy and creates a thermogram profile. The above two methods are highly dependent on illumination sources, but this method eliminates that reliance. Thermography can detect electromagnetic spectrum from 9 to 14 µm.
Thermogram produces extreme background for warm objects than cooler items. Through the thermographic image, we can easily differentiate between humans, animals, or other objects.
Night vision technology evolved through numerous generations. Each generation overcomes the drawbacks of earlier generations. We can classify the NVDs into five different generations from their beginning.
Generation 0 night vision scopes were developed during World War II and the Korean War. German army developed this technology parallelly in the 1940s to 1950s. These NVDs relied on a powerful IR light source. However, the zeroth generation devices are now obsolete.
The 1st generation NVDs used ambient light sources like starlight, moonlight, or other natural light sources instead of powerful IR light. Using these devices, you can view objects clearly at night up to 75 yards. These devices are good for close-range observation.
Night vision technology opened a new era from the 2nd generation devices. These units improved the image intensifier tube using the newly developed microchannel plate with S-25 photocathode. Their image quality enhanced largely from the earlier generations.
The development of photocathode was a demand from the beginning of night vision technology. Luckily, the 3rd generation NVDs improved this part using gallium arsenide photocathode that improved resolution greatly. These devices can cover a great range in total darkness and are usable for military, surveillance, and other usual purposes.
The modern night vision scopes that were developed after the 1990s are referred to as 4th generation NVDs sometimes. However, the US army does not recognize these devices yet. Still, the performance and price make them different from Gen III. That’s why some manufacturers entitled them as 4th generation scopes.
Night vision scopes are a little bit different from day vision scope. Some NV scopes can be used in the daytime also. But most of the day vision scopes don’t work at night.
After learning about night vision technology and generations, let’s focus on the buying factors. The following considerations will help you to pick the right scope from lots of options available on the market.
Magnification helps to view the close look of the target. Most of the scopes come with fixed and variable zoom options. If you are a long-range shooter or big game hunter, then you need more magnification device than the short-range shooter.
Fixed magnification NVDs work only at a certain power such as 4x. On the other hand, variable magnification works for versatile zooming. Usually, variable zooming is more convenient than a fixed option.
The objective lens is located just opposite your eyepiece. The larger objective lens provides a brighter and clear image. But excessive larger ones may make the units heavy. So, you have to research for a while to get the perfect size objective lens.
Normally, a long-range shooter needs a 50mm or more diameter lens. However, a 25mm lens is okay for a short-range like 100 yards or lesser range shooting.
Magnification and objective lens are two important parameters of a night vision scope. Most of the manufacturers mention these features in each scope. If a scope comes with 4-10x40, it means the magnification of the device is 4-10 and the 40 denotes the objective lens diameter. And the magnification is variable type, so you can change this according to your requirement.
Resolution helps to get a good depth of perception and perfect image. The best night vision scopes produce wonderful resolution images at the center and blurry images around it. Lines per millimeter (lp/mm) is the measuring unit of resolution. If you want the best quality image, a high-resolution NVD is necessary. Field of view and some other things are also important.
Typically, night vision scopes lens come with four different types of coating. These are single coating, fully coating, multi-coating, and fully multi-coating lens. The fully multi-coated lens is the most wonderful one that reduces glare and maximizes light transmission. This also ensures a sharp and high-quality image.
These are the most important aspects of an NV scope that need to be checked perfectly before buying one. Don’t overlook this guide when you are planning to pick your NVS. There are other parameters too based on which you can decide whether you would go for any particular scope or not. But, for a beginner, these are the most essential ones. So, get the perfect night vision scope for rifles you deserve.