Basic Training: How Do Thermal Cameras Work?

If you’re reading this, you’ve probably got questions about thermal cameras. What are they, and how do thermal cameras work? Can thermal cameras see through walls?

Indeed, thermal devices are powerful imaging tools that are used in a variety of industries, including law enforcement, military, and hunting, as well as search and rescue. They are unlike traditional cameras that rely on visible light in that thermal imaging detects heat signatures. That means users can see in complete darkness, through fog, and in many other conditions where standard optics would usually fail.

So, exactly how do thermal cameras work, anyway? Do they have limitations?

Thermal Imaging Science

How do thermal cameras work? Infrared technology lies at their core. All objects – both animate and inanimate – emit infrared radiation, which is a form of electromagnetic energy invisible to the human eye. How much infrared radiation an object emits depends on its temperature. A human, for example, would emit more than a rock.

Thermal cameras have a special sensor known as a microbolometer that detects radiation. The sensor reads different heat levels and translates them into a thermal image, which is then displayed as a visual representation of temperature differences. Warmer objects show up as brighter shades, while cooler objects are darker.

Advanced thermal cameras even produce detailed heat maps. They are invaluable in many professional applications.

Thermal Camera Components

To really understand how thermal cameras work, you must be aware of their key components. Thermal cameras, after all, are complex devices made up of several elements:

• Infrared Lens – The infrared lens focuses the infrared radiation onto the sensor.
• Microbolometer Sensor – This sensor captures thermal radiation. Then it converts it into an electrical signal.
• Processor & Software – The device includes a computer that translates data into a readable image.
• Display Screen – A thermal imaging display screen shows the processed thermal image to the user.
• Additional Features – Some thermal imaging models include extras like digital zoom, multiple color palettes, and even Wi-Fi connectivity for image sharing.

Can Thermal Cameras See Through Walls?

It’s a common misconception that thermal cameras can “see” through walls. The fact is that thermal cameras do not have X-ray vision. What they do is detect heat differences on surfaces – not through them.

Let’s say a person is standing behind a thin wall. It’s true that the camera might pick up residual heat where their body warms the surface. But a solid, insulated wall will block thermal signatures completely. That’s the reason why law enforcement officers use thermal cameras for tracking people in open areas rather than inside buildings.

Law Enforcement Applications

Both police and military personnel often rely on thermal imaging for improved situational awareness, search-and-rescue missions, and target acquisition.

In high-risk scenarios, thermal cameras provide law enforcement with critical intelligence that can make or break a mission. A few of the ways they use this technology include:

• Tracking Suspects – Thermal cameras are great to detect individuals who might be hiding in darkness or behind light cover.
• Search and Rescue – The imaging can also be used to locate missing persons in remote or hazardous areas.
• Surveillance Operations – Law enforcement uses thermal cameras to monitor criminal activity without visible light.
• Tactical Advantage – Thermal imaging cameras help identify hidden threats before engaging with them.

Hunting and Thermal Imaging

Thermal cameras give hunters a significant advantage in the field. It can be hard to spot many animals with the naked eye thanks to their natural camouflage. With thermal imaging, hunters can see detected body heat, so game is visible whether it’s in a dense forest or an open field.

Thermal cameras also provide hunters with ethical benefits. Thanks to the technology, they can be sure they’re taking clean shots since they can clearly identify their targets and surroundings before ever pulling the trigger.

Military and Tactical Uses

It only makes sense that thermal imaging would play an important role in military operations. The ability to see heat signatures gives soldiers an edge in combat environments including during surveillance and navigation.

Many military-grade thermal optics are even integrated with ballistic calculators and rangefinders to improve accuracy and efficiency in the field.

Some of the military operations that benefit from thermal imaging technology include:

• Nighttime Operations – Troops can navigate terrain without artificial light thanks to thermal cameras. That reduces their risk of detection.
• Vehicle Detection – With heat signatures, it’s easier to spot enemy vehicles – even if they’re camouflaged.
• Perimeter Security – Thermal cameras help soldiers, sailors, and Marines to detect intruders, even when they’re in total darkness.

How Thermal Cameras Perform in Different Environments

Thermal imaging technology works best when it can detect noticeable temperature differences between different objects and their surroundings. But that means that environmental conditions can impact the optics’ performance. Some of these conditions include fog, smoke, water, glass, and cold.

Fog and Smoke

Thermal imaging is unlike visible light cameras. It can penetrate light fog and smoke. That makes it a useful tool for firefighters and emergency responders.

Water and Glass

Because infrared radiation doesn’t effectively pass through materials like water and glass, thermal cameras don’t see well through these mediums.

Cold

When it’s extremely cold, thermal cameras will still work, but they might show less contrast if everything around is at a similar temperature.

Thermal Imaging vs. Night Vision

Sure enough, both thermal imaging and night vision technologies can improve visibility in low-light conditions. But they operate in different ways and serve distinct purposes.

As we discussed, thermal imaging detects heat signatures. That makes it perfect for spotting objects based on temperature differences. It doesn’t require any ambient light, so it also works well in total darkness. These qualities make thermal cameras especially useful if you want to detect camouflaged objects, track animals or people, and find your way through fog or smoke.

On the other hand, night vision amplifies the available light. That can be minimal light from the moon stars, or infrared illuminators. The technology provides more detailed visuals than thermal imaging, so users can even read markings, recognize faces, and distinguish other fine details. Unfortunately, however, night vision optics don’t work in complete darkness unless they’re paired with an infrared light source. Night vision also struggles in dense fog or smoke, and in extreme weather conditions.

Invest in Thermal Technology

When it comes to hunting, law enforcement, military, and surveillance, thermal cameras offer so many advantages. When you understand how these optics work, you can make a more informed decision about selecting the perfect device to suit your own needs.

Night Vision Guys features all sorts of high-quality thermal optics from leading brands. That way, both professionals and enthusiasts get the best possible performance. Head on over to the site and explore the selection of thermal cameras to find the perfect choice for your next mission or outdoor adventure.