Thermal imaging cameras are becoming more and more available. Now, the market has many options for manufacturers of thermal imaging cameras, each of which is good in its own way. To name a few there are: AGM Global Vision, Pulsar, ATN, Bering, NVision, Trijicon, and many others. But, before you buy the scope, you need to understand a little bit about the terminology and application of the device. 

Perhaps this article will be useful for those who are choosing their first thermal imaging sight or who want to make a more conscious purchase.

Things to consider before buying a thermal scope

Thermal sights are probably the most technologically advanced thermal imaging devices. In addition to the advanced technology of capturing and reproducing an image based on the heat of the object, they have installed software that will allow you to shoot a weapon, and in one shot, zero the optic depending on the distance, and other functions. They are usually mounted directly to the weapon and can withstand huge recoil: there are no structurally fragile elements like in the NVD. They also make them the most waterproof, assuming the harshest conditions during hunting or military operations. That's why thermal imaging sights are the most expensive of all thermal imaging cameras. 

All sights easily recognize the target by receiving and processing heat from objects into a picture that can be seen with the naked eye. 

Before you buy a thermal sight you should consider the following characteristics:

Magnification

The magnification is the ability to determine the exact location of the target, from which heat emanates. The higher the magnification, the more it affects the image resolution you see through the sight. The number before the «x» sign indicates the zoom. It shows how many times the image in the reticle is larger than that visible to the simple eye. All thermal scopes come with a fixed base magnificaition. That is the optical magnification. Models of thermal sights have a digital zoom, which in fact stretches pixels within the display screen to increase magnification.

Resolution of the scope and sensor

A thermal sensor with a resolution of 640x480 will always produce a clearer image than a 384x288 sensor, and certainly more than 320x240. No one doubts that a higher resolution TV shows better than a lower resolution TV. So with thermal imaging cameras - if you see just a white spot in the device with the 384x288 matrix, the device on the 640x480 matrix will allow you to understand what is actually is in front of you. 

Do not confuse the resolution of the microbolometer (matrix) with the resolution of the display. The matrix resolution can be 384x288 pixels, and the display extension can be 800x600 pixels (as, for example, at the AGM Secutor TS50-384 sight).

Scope detection and recognition range

The object detection range refers to the distance a thermal device is able to pick up heat at. The recognition range is the distance at which the device can accurately recognize and distinguish animals from humans, other game animals, etc.

If you are hunting in the desert or the mountains where long-range shooting is possible - at 400 yards and beyond - you will need a sight with a long-range of detection and target recognition. These are sights with large lenses (a focal distance of 50 mm and more), capable of detecting a target at a distance of 1800 - 2000 yards.

If you hunt boars in the woods and know that you will not shoot further than 200 yards at night (for reasons of caution, or simply because your gun is not capable of a long-range confident shot). In this case, the sight with 25 - 38 mm lenses will be enough. Their detection range is a little over 1000 yards but they have a larger field of view which is better suited for close range hunting.

Reticle pattern

The reticle is designed to help accurately point the weapon at the target. 

The reticle on thermal imaging sights can be a variety of different reticles typically selected by the user. Most thermal scopes come with a duplex, mil dot, chevron, or even a single dot.  Each of these reticles may have their advantages for a hunter. For example, a duplex is convenient for night hunting. A single dot or circle dot reticle is needed for better accuracy as you would want the finest point of aim possible.

Refresh Rate

The image in the sighting eyepiece is updateing constantly. The higher the frame rate, the shorter the delay time. This is especially important when shooting at moving targets. Thus, the frame rate of the screen as well as the pixel response should be no less or superior to the capabilities of the microbolometer sensor.

For example, a boar runs at a speed of up to 10 m/sec. The animal will move almost half a meter during one frame refresh.

Lens diameter

The larger the lens, the more light it transmits and the brighter the picture becomes. 

The larger the diameter of the lens, the bigger the field of view of the reticle will be. 

The bigger the diameter of the lens, the more expensive the device is due to the components required to make a thermal lens. 

Battery life

Thermal sights have more powerful light optics than other night vision devices. Most often they operate autonomously 3-4 hours or more from a pair of CR123 batteries. But there are other options. 

Most thermal devices can connect to additional external power sources via a USB port on the unit. 

Find out these details before buying the device.

Warranty

Going to buy any expensive item, it makes sense to inquire about the warranty obligations of the seller or manufacturer and the possibility of rapid repair. Out of warranty device repairs can range from hundreds or thousands of dollars. The main thing is that you do not have to be left alone with a broken device.

The manufacturer's reputation is important when choosing a device. If the manufacturer is unknown in the world market, has no official distributors in your country, we do not recommend experimenting with its sights at your own expense. 

Choose always only the best!