The Ultimate Buyer's Guide for Purchasing Infrared Lens for aerospace

A comprehensive guide to purchasing a thermal infrared camera for various applications

Thermal infrared cameras, also known as thermal imaging cameras, are specialized devices used to detect and capture images of the infrared radiation emitted by all objects - even living animals and humans. This technology works by detecting the heat energy that radiates from objects in the form of infrared radiation, which is invisible to the naked eye.

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Infrared imaging cameras are used in a wide range of applications, including home and building inspection, electrical and mechanical inspection, firefighting, search and rescue operations, law enforcement and security, wildlife observation, and medical imaging.

The cameras detect temperature differences and create images using color palettes that represent the temperature variations. These images can be displayed in real-time on a screen or recorded for later analysis.

Thermal infrared cameras are highly accurate and reliable, allowing for the detection of defects, anomalies, or hidden problems in those objects. They are also highly useful in situations where visibility is limited, such as in smoke, darkness, or harsh weather conditions.

Infrared thermal cameras are available in various models with different features, including resolution, field of view, temperature range, and sensitivity. They are also available in handheld and mounted configurations, with additional accessories to enhance their functionality.

Key features to consider when purchasing a thermal infrared camera

1. Temperature range: The temperature range refers to the minimum and maximum temperatures that the camera can measure accurately. It is important to select a camera with a range that suits the intended application.
2. Thermal sensitivity: Thermal sensitivity refers to the smallest temperature difference that the camera can detect. A camera with higher sensitivity can detect smaller temperature differences, making it more accurate.
3. Resolution: Resolution refers to the number of pixels in the image, and higher-resolution cameras produce clearer and more detailed images.
4. Field of view: Field of view refers to the area of the scene that the camera can capture. A wider field of view is useful for capturing larger scenes, while a narrower field of view is better for more detailed analysis.
5. Image and video recording: Cameras that can record both images and videos can provide more detailed analysis and documentation.
6. Battery life: The battery life of the camera is an important consideration, especially for field use.
7. User interface: A user-friendly interface can make it easier to operate the camera and access its various features.
8. Portability: The size and weight of the camera can affect its portability, making it easier or harder to transport and use in different settings.

Considerations Before Buying a Thermal Infrared Camera

Budget - The budget for purchasing a thermal infrared camera can vary depending on the intended application and the level of features and capabilities required. Thermal infrared cameras can range in price from a few hundred dollars for entry-level models to tens of thousands of dollars for high-end professional cameras.

When determining the budget for an infrared thermal camera purchase, it is important to consider the intended application and the level of accuracy and detail required. Cameras with higher resolution and sensitivity may be more expensive but may be necessary for certain applications, such as medical imaging or advanced research.

It is also important to consider the level of support and training offered by the camera manufacturer or distributor. Cameras with comprehensive manuals and training programs may be more expensive but can help to improve the user experience and efficiency of the camera.

Finally, it is important to consider the overall value of the camera and the potential return on investment. Investing in a higher quality camera with greater accuracy and durability may result in cost savings in the long term, as it can reduce the need for repairs or replacement, and improve the accuracy and efficiency of inspections or research.

Resolution - Resolution is a key specification to consider when choosing a thermal infrared camera. It refers to the number of pixels in the camera's image sensor and is an indicator of the level of detail that the camera can capture.

Higher-resolution cameras produce clearer and more detailed images, which can be important for certain applications where small temperature differences or anomalies need to be detected.

Resolution is typically measured in pixels (horizontal x vertical) and can range from as low as 80x60 pixels to as high as 640x480 pixels or more. However, higher-resolution cameras tend to be more expensive and require more processing power to analyze the captured images.

It is important to note that the resolution of a camera is not the only factor that determines the level of detail in an image. Other factors, such as the quality of the lens and detector, the thermal sensitivity of the camera, and the level of noise reduction applied to the image, can also affect image quality.

Imaging and Video Recording - Image and video recording capabilities are important features to consider when selecting an infrared imaging camera. The ability to record images or videos of the captured thermal data can be useful for documentation, analysis, and reporting purposes.

Many heat infrared cameras come with built-in memory or have the ability to store data on external memory cards or USB drives. Some cameras also can stream live video or data directly to a computer or mobile device.

When it comes to image and video quality, cameras can vary in their capabilities. Some cameras may have the ability to capture higher-resolution images or videos, while others may have the ability to capture higher frame rates for smoother video playback.

It is important to note that the size of the memory or storage capacity of the camera can affect the length of the recording time. Additionally, the type of file format used for recording can affect the amount of storage space required and the ease of use for analyzing or sharing the recorded data.

Brand and Reputation - When considering an infrared thermal camera purchase, it is important to take into account the brand and reputation of the manufacturer. The brand reputation can indicate the quality of the camera, the level of customer support provided, and the overall reliability of the product.

There are several well-known brands in the thermal infrared camera market, including FLIR Systems, Testo, Seek Thermal, and FLUKE. These companies have a strong reputation for producing high-quality, reliable cameras that are used in a wide range of applications.

Brands like Teslong are new to the market, but build high-quality products with many features of higher-priced brands. Teslong may not be as well known, but they have a history of building reputable goods for sale on Amazon and their website with many positive reviews and excellent customer support.

When considering a specific brand, it is important to research its customer support services, including warranties, technical support, and training programs. The level of customer support provided can be a good indicator of the quality of the camera and the commitment of the manufacturer to its customers.

In addition, it can be helpful to read customer reviews and ratings of the product. This can provide insights into the user experience, including ease of use, accuracy, and reliability of the camera.

Customer Support and Warranty - Customer support and warranty are important factors to consider when purchasing an infrared imaging camera. These factors can help ensure that the camera performs as expected and is backed by the manufacturer in case of any issues or defects.

Customer support services can include technical support, training programs, and repair services. It is important to choose a manufacturer that offers comprehensive customer support services to ensure that the camera is easy to use and that any issues can be resolved quickly and efficiently.

Warranty is another important factor to consider when purchasing an infrared thermal camera. A warranty protects against any defects or issues with the camera for a specified period. The length of the warranty can vary depending on the manufacturer and model of the camera, but it is generally recommended to choose a camera with a warranty of at least one year.

It is important to read the terms and conditions of the warranty carefully to understand what is covered and what is not covered. Some warranties may exclude certain types of damage, such as damage caused by misuse or accidents.

In addition to the warranty, some manufacturers may offer extended warranty or maintenance plans for an additional fee. These plans can provide additional protection and peace of mind for the user.

Teslong offers a 1-year warranty for their products to be free of defects caused by the manufacturer. You can also call Teslong customer service during business hours (PST) to ask them any questions about their product and they will be happy to assist you.

Accessories - There are several accessories and add-ons available for thermal infrared cameras that can enhance their performance and functionality. Some popular accessories include:

1. Tripods and mounts: These accessories allow the camera to be mounted on a stable surface, providing a steady image and reducing operator fatigue.
2. External power sources: These can extend the battery life of the camera and provide additional power for extended use.
3. Lenses: Different lenses can be attached to the camera to adjust the field of view, allowing for more flexibility in different applications.
4. Software: Some manufacturers offer software that can enhance the analysis and interpretation of the images and videos captured by the camera.
5. Carrying cases: These protect the camera during transport and storage and can make it easier to carry the camera on the go.
6. Radiometric data logging: This accessory can provide accurate temperature readings and can be used to track temperature changes over time.
7. Remote control: Some cameras come with remote control accessories that allow for hands-free operation, providing greater flexibility and ease of use.

When considering accessories and add-ons for an infrared imaging camera, it is essential to choose accessories that are compatible with the specific camera model and meet the requirements of the intended application. Choosing the right accessories can help enhance the performance and usability of the camera, and provide greater flexibility and convenience for the user.

Types of Thermal Infrared Cameras

There are several types of infrared thermal cameras available on the market, each with its own unique features and capabilities. The most common types of heat infrared cameras include:

1. Handheld cameras: Handheld cameras are portable and easy to use, making them ideal for a variety of applications such as building inspections, electrical and mechanical inspections, and HVAC diagnostics.
2. Fixed-mounted cameras: Fixed-mounted cameras are typically used for continuous monitoring of large areas or processes, such as in industrial manufacturing and process control applications.
3. Pan-tilt-zoom (PTZ) cameras: PTZ cameras are motorized and allow for remote control of the camera's movements, providing greater flexibility and versatility for surveillance and monitoring applications.
4. Optical gas imaging (OGI) cameras: OGI cameras are designed specifically to detect and visualize gas leaks, making them ideal for use in the oil and gas industry, chemical plants, and other industrial applications.
5. Aerial cameras: Aerial cameras are mounted on drones or aircraft and can be used for aerial inspections, surveillance, and monitoring.

Each type of camera has its own advantages and limitations, and the choice of camera will depend on the specific application and requirements.

Technical Specifications to Consider

Thermal Sensitivity - Thermal sensitivity is an important specification to consider when choosing an infrared imaging camera. It refers to the smallest temperature difference that the camera can detect. The sensitivity is measured in units of temperature difference (in degrees Celsius or Fahrenheit) per unit of infrared radiation received by the camera (typically milliKelvins or mK).

For example, a camera with a thermal sensitivity of 50mK can detect a temperature difference of 0.05°C between two objects. A camera with higher sensitivity will be able to detect smaller temperature differences, making it more accurate and useful in applications that require precise measurements.

Thermal sensitivity can be affected by various factors, such as the quality of the camera's detector, lens, and electronics, as well as the level of ambient temperature and humidity. As a result, different cameras may have different levels of sensitivity even if they have the same resolution or temperature range.

Temperature Range - The temperature range of a heat infrared camera is the minimum and maximum temperature that the camera can measure accurately. This range is typically specified by the manufacturer and is an important consideration when selecting a camera for a specific application.

Most infrared thermal cameras have a temperature range that spans from -20°C to 120°C or higher, with some specialized cameras capable of measuring temperatures as high as °C or as low as -50°C. However, the temperature range of a camera may vary depending on the model and brand.

Field of view - Field of view (FOV) is an important specification to consider when selecting an infrared imaging camera. It refers to the area of the scene that the camera can capture.

FOV is typically measured in degrees and can range from as narrow as 9 degrees to as wide as 60 degrees or more. A wider FOV is useful for capturing larger scenes or objects, while a narrower FOV is better for a more detailed analysis of smaller objects.

It is important to note that the FOV of a camera can also affect the camera's spatial resolution. A narrower FOV can provide higher spatial resolution for smaller objects or features, while a wider FOV can provide a lower spatial resolution but can capture larger areas.

Some heat infrared cameras have interchangeable lenses, which allow the user to switch between different FOVs depending on the application. This can be useful when the user needs to switch between close-up analysis and capturing larger scenes.

Image Refresh Rate - Image refresh rate is an important factor to consider when shopping for a thermal infrared camera. The refresh rate determines how quickly the camera updates the thermal image displayed on the screen. A higher refresh rate means that the camera can capture and display changes in temperature more quickly, providing a smoother and more accurate representation of the thermal image.

In applications where there is movement or rapid changes in temperature, such as in electrical or mechanical inspections, a higher refresh rate is critical to capture and analyze the thermal image accurately. A lower refresh rate can lead to blurring or distortion of the image, making it difficult to identify and diagnose potential issues.

However, a higher refresh rate often comes at a cost of increased power consumption, which can impact the battery life of the camera. It is important to balance the need for a high refresh rate with the practical limitations of the camera, such as battery life and budget.

Overall, the image refresh rate is an important consideration when choosing an infrared imaging camera, especially for applications that require real-time monitoring and analysis of thermal images.

Lens Options - Some of the common lens options for thermal infrared cameras are:

1. Fixed lenses: These lenses have a fixed focal length and are suitable for applications where the distance to the object being measured is constant.
2. Zoom lenses: These lenses have adjustable focal lengths and can be used to change the magnification and field of view of the camera. This makes them suitable for applications where the distance to the object being measured may vary.
3. Macro lenses: These lenses are designed for close-up imaging and can be used to measure the temperature of small objects or features.
4. Telephoto lenses: These lenses have a long focal length and narrow field of view, making them suitable for applications where the object being measured is far away.
5. Wide-angle lenses: These lenses have a short focal length and wide field of view, making them suitable for applications where a larger area needs to be imaged.
6. Fisheye lenses: These lenses have a wide field of view and are suitable for applications where a panoramic view is required.

Choosing the right lens for an infrared imaging camera is important, as it can impact the accuracy and resolution of the temperature measurements. Factors such as the distance to the object being measured, the size of the object, and the required level of detail will all influence the choice of lens.

Display Options  - Some of the common display options for heat infrared cameras are:

1. Monochrome LCD displays: These displays provide a black-and-white image, which can be easier to interpret in some applications. They are typically less expensive than color displays.
2. Color LCD displays: These displays provide a color image, which can make it easier to identify different temperature ranges or areas of interest in the image.
3. Touchscreen displays: These displays allow the user to interact with the camera and adjust settings or analyze data directly on the screen. They are often used in more advanced applications.
4. High-resolution displays: These displays provide a higher level of detail and resolution, which can be useful for applications where a high degree of accuracy is required.
5. Wireless display options: These displays allow the user to remotely view the image and control the camera from a distance. This can be useful in applications where the camera needs to be mounted in a difficult-to-reach location.
6. Video output: Some infrared imaging cameras offer video output capabilities, which can be useful for recording or streaming the thermal image to another device.

Factors such as the level of detail required, the need for color or monochrome images, and the need for remote viewing or control will all influence the choice of display option.

Measurement Modes - There are several measurement modes that are commonly used in thermal infrared cameras, including:

1. Spot measurement mode: In this mode, the camera measures the temperature of a small spot on the object being observed. The size of the spot can usually be adjusted.
2. Area measurement mode: In this mode, the camera measures the temperature of a larger area on the object being observed. The size of the area can usually be adjusted.
3. Line measurement mode: In this mode, the camera measures the temperature along a specific line on the object being observed. This mode is often used to measure the temperature profile of a surface or to detect temperature gradients.
4. Isotherm measurement mode: In this mode, the camera displays areas of the image that are above or below a specific temperature threshold. This mode is useful for identifying areas of interest in the thermal image.
5. Delta temperature measurement mode: In this mode, the camera displays the temperature difference between two points on the object being observed. This mode is useful for detecting temperature gradients and identifying areas of interest where there are temperature differences.

These different measurement modes can be useful in different applications, depending on the specific requirements of the task at hand.

Common Applications of Thermal Infrared Cameras

Thermal infrared cameras are versatile tools that have a wide range of applications in various industries and fields. Some of the key applications of heat infrared cameras include:

1. Building inspections: Thermal infrared cameras can be used to identify areas of heat loss or moisture intrusion in buildings. This can help to improve energy efficiency, identify potential structural issues, and prevent mold growth.
2. Electrical inspections: Thermal infrared cameras can be used to identify hot spots in electrical systems, which can indicate potential issues with equipment and help to prevent electrical fires.
3. Mechanical inspections: Infrared imaging cameras can be used to identify areas of excess friction or heat in mechanical systems, which can help to prevent equipment failure and improve efficiency.
4. Medical imaging: Thermal infrared cameras can be used for non-invasive medical imaging, such as identifying areas of inflammation or nerve damage.
5. Wildlife Research: Thermal infrared cameras can be used to monitor wildlife populations and behavior, as well as to track and locate animals in the wild.
6. Firefighting: Thermal infrared cameras can be used by firefighters to identify hot spots and locate victims in smoke-filled environments.
7. Security and surveillance: Infrared imaging cameras can be used for perimeter security and surveillance, as they can detect movement and heat signatures in low-light or dark environments.
8. Agriculture: Heat infrared cameras can be used to monitor crop health and irrigation, as well as to detect pests and diseases in plants.

Overall, the wide range of applications for thermal infrared cameras makes them a valuable tool for many different industries and fields.

Shop Teslong Thermal Cameras

In summary, when choosing the best heat infrared camera to buy, there are several important factors to consider. First, it's important to consider the specific application that the camera will be used, as this will influence the required resolution, accuracy, and temperature range of the camera.

Next, consider the available features of the camera, such as the type of detector, lens options, display options, and measurement modes. Choose features that will meet the requirements of the application and allow for the most accurate and efficient use of the camera.

Other factors to consider include the size and weight of the camera, as well as its durability and ruggedness. This is particularly important if the camera will be used in harsh environments or if it needs to be portable.

Finally, consider the cost of the camera, as well as the availability of technical support and training. Choose a camera that fits within your budget, but also provides the necessary features and support to get the job done.

IRLENS Product Page

The best thermal imaging cameras allow you to explore the world in a whole new way. They let you see, measure, and capture temperature differences, accurately and from a safe distance.

Beyond the visible spectrum, there is an unseen world of heat radiation. Arty infrared film photographs aside, the practical uses of thermal imaging devices – also known as infrared thermal imagers – once belonged only to military and professional budgets.

Now anyone can access thermal imaging, whether you want to see heat sources in dark places – ideal for wildlife spotting – or identify where heat is being lost from your property to save on energy bills. If you simply want to measure temperatures, you may prefer our guide to the best infrared thermometers, but for HVAC, electronics, and plumbing these are now essential.

Find out more about how thermal imaging cameras work at the bottom of this guide. Below are the best thermal-imaging cameras you can buy right now, which I have either personally tested or sought expert advice and first-hand experience of.

The Quick List

Best thermal-imaging cameras

Why you can trust Digital Camera World Our expert reviewers spend hours testing and comparing products and services so you can choose the best for you. Find out how we test.

Best thermal-imaging camera overall

The FLIR ONE Edge Pro is a wireless thermal-visible camera for camera phones and iPads. It's designed with a spring-loaded clip, which allows different users (or companies with several workers) to attach the camera to both iOS and Android smartphones and tablets. Unlike previous FLIR thermal imaging models that plugged into the bottom of the , the ONE Edge Pro doesn't actually have to be connected at all – and can be used up to 30 meters (100ft) away with a Wi-Fi and Bluetooth connection; something I found very handy.

It is a compact, easy-to-use imaging device for builders, mechanisms, building inspectors and even homeowners who want to see how much heat their home is leaking! It's also IP54-rated, so while it can measure temperatures up to 400°C (752°F) and has a maximum 1.5-hour battery life, it's also reasonably rugged – not usually true of attachments.

Teledyne FLIR promises that it's easy to recognize where problems are located and identify targets, thanks to FLIR's MSX (Multi-Spectral Dynamic Imaging), 160 × 120 (19,200 pixels) thermal resolution and VividIR, which combines multiple image frames together to deliver a clearer image.

(The company also offers a budget version of this camera (no 'Pro' at the end of the name – but I've yet to review it personally).

My full review of the FLIR One Edge Pro with samples

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Best rugged thermal-imaging camera

The FLIR C3-X and FLIR C5 are good-looking compact thermal imagers that are well suited to DIYers and contractors. With a rugged body that’ll survive a bit of workplace rough-and-tumble, both have two cameras and a 5-megapixel optical lens. The IR maxes out at 160 x 120 on the pricier C5, allowing it to take advantage of Flir’s MSX technology. This patented method uses an edge-detection algorithm on the higher-resolution visual light image, overlaying this with the IR image to make the picture easier to comprehend.

Both versions have a 3-inch touchscreen and can store around 500 images onboard to transfer via Micro USB. The ability to type notes via a touch keyboard can be handy, too. If you can stretch to it, the FLIR C5 model adds more analysis features and Wi-Fi so you can get images to your and to your software.

FLIR’s analysis software, FLIR Tools, allows you to change the color palettes and take readings from 4,800 measurement points in the image files, a little like using the eyedropper in Photoshop.

Read my full FLIR C5 review for more details

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Best compact thermal-imaging camera

This amazingly compact device nevertheless beats more expensive alternatives in a number of ways. It only works when connected to a , and the connector – a lightning or USB-C plug – must be specified at purchase. But the app is good and offers a choice of easy or pro modes.

Another stroke of genius is the magnetically attachable macro lens, which is ideal for those examining circuit boards or other electronics, making this a very versatile tool. I worry that for some the connection might be delicate, but it is reversible (both USB-C and Lightning ports are on offer) and you can see the level of detail in which I tested the device against simple insulation, plumbing, and electronics situations.

Still, when trying this, I found it very handy, and the accessible price makes sense for occasional DIY use or – perhaps – getting a cheaper (one of the best burner smartphones) so you don't worry about dropping your daily driver into the engine you're working on!

Check my full InfiRay P2 Pro review

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Best thermal-imaging camera for construction

This thermal-imaging camera is easy to use in the workplace but fully equipped with Wi-Fi and Bluetooth to share data with a . Held with a pistol grip, the image can be frozen with a trigger and saved using the camera icon below the screen. The design, with a built-in lens cover and rubber guards to protect the 3.5-inch screen, is strong and IP53 dustproof.

The device includes a picture-in-picture context function, which places the thermal image in the centre of a frame with a visual image around the outside providing context. Also useful on-site is the lock feature which fixes the minimum and maximum temperature (like an exposure lock).

Bosch also provides a supporting app so you can transfer images beyond the 600 the device will hold. This is great for additional analysis and report creation, and the radiometric data is there for later analysis (but it’d still be nice to store more onboard).

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Best thermal-imaging drone

If you're looking for a thermal drone, then the Mavic 3T Enterprise is a great choice, combining good value and portability with a good quality camera block and software. I had a lot of fun testing the drone because – while I wasn't able to have a real search and rescue scenario – my family were able to try hiding from me and the drone's high-resolution thermal sensor made it difficult, while the telephoto optical one finished the deal.

A certain amount of training or practice is needed to get to grips with this device compared to the most basic consumer drones, and some US government agencies aren't allowed to buy DJI, but if you're able to get in the air you get side-by-side thermal video next to optical.

The thermal video is 30Hz, too, which makes it easy to locate people or wildlife – as well, of course, as survey buildings for inefficient thermal properties. Price-wise the Enterprise series isn't cheap, but the controller is good quality too, and it is competitive with other brands like Autel while holding the edge on usability grounds.

(If you can't opt for DJI because of legal concerns – ironically the freedom to choose drones in the USA is somewhat curtailed for some jobs – then check our guide to the best non-DJI drones).

UPDATE: Although we're still waiting to review it, the Mavic 3T has effectively been replaced by the Matrice 4T as of an announcement in January . You can see the device on the DJI store (but there might be some good deals on the cheaper – and more than adequate for most Mavic 3T for a while)

Check my full review of the Mavic 3T to see sample videos.

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Best thermal-imaging camera for spot measurement

Hikmicro's E1L shows a good, rugged workshop thermal camera – with a laser spot for taking targeted measurements – doesn't need to be excessively costly. When I tested it I found the simple trigger operation makes it well suited for straightforward work, while the 25Hz refresh rate is judder-free making it smooth to operate.

Officially IP54 rated, and convincing in the hand this felt like a good choice, especially as it comes in for a lower price than some competitors. I wouldn't choose this for its built-in software or if you need to make frequent reports that include visual images (there is no optical camera), but in a workshop or with clients where the work is more immediate and you need to see the issue and get the reading this is quick and feels good in the hand.

You can also store images to a memory card and copy to computer later, so those features are there – they simply aren't at the sophisticated level that FLIR's EX-series has reached (but that costs twice as much).

Check my full review of the Hikmicro E1L.

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Best thermal-imaging camera for hunting

Combining a 160x120 pixel sensor with a 640 x 480 pixel LCD display means the Scout TK has the resolution and tech to identify a mammal – a person or a deer, say – hiding at around 100 yards (90m) away while being no harder to use than a traditional scope. That’s not a stunning level of detail, but without the scope your eyes might well not make out targets at a much shorter distance, especially in low light, giving this device a broad range of security and hobby uses.

If resolution, and, by extension, greater range, is a need, then you'll need deeper pockets – serious professionals can, after all, look for the 640 x 512 pixel FLIR Scout III but the price is around four times higher

The compact size and rechargeable battery boost the practicality; there will be no trouble fitting this into a decent coat pocket. The USB image download is convenient, and there's a cable included too, although no wireless transfer.

With a fixed field of view (20˚), the controls are not challenging: just brightness and the option to switch the color palette (White Hot, Black Hot, InstAlert, Graded Fire, Color Wheel and others). A single button handles recording, with a short press for a still and a long press for video. The 9Hz refresh rate is fast enough to make hand-holding practical.

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Best thermal-imaging smartphone

The CAT S62 Pro is designed to take serious abuse, with the construction that means that it can be dropped without having to worry about dents or cracking its Gorilla Glass 6 screen. With an IP68 rating, CAT phones can be submerged in 3m of water, too, without fear of ingress. And this industrial design also comes with some useful additional features that you don't find on a – including a very capable thermal imaging camera built on the FLIR 3.5 sensor (160 x 120).

This is useful because it reduces the things you need to carry and avoids any connecting with IR cameras via Bluetooth or cables. The , too, is a perfectly serviceable affair with a 660 Octo Core 2GHz CPU that will run your favorite apps and 6GB storage for them. Even if it may lack some of the refinements of the top camera phones, it has a 12MP Sony sensor, comes with Android 10, and supports the Android Enterprise feature set.

Note: The even older CAT S61 – which is getting harder to come by, but is still available in places – had a lower resolution IR camera, but also boasted laser measuring, so offering an alternative with even more flexibility.

Read our full review of the CATS62 Pro

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Best pro handheld thermal-imaging camera

FLIR’s rugged E-series, of which the E8-XT is the top of the line, and I have reviewed the E5-XT, which has a similar build but half the thermal resolution. It offers the advantages of the company’s image enhancement, which merges visible light with the IR thermograph for easier-to-understand imagery. At this price, it seems a little unfair that the visible light camera is only 640x480, but in this context, it works well enough.

Of more concern to a working professional is the combination of Wi-Fi/Bluetooth and the FLIR Tools app, which enables timely delivery of your assessment, with imagery, to clients. This is well-realized, easy to operate, and can also be used, via screen recordings, to capture video from the camera.

When you’re regularly working in rough environments, the E8 represents the kind of reliability you need. The autofocus makes it easy to use and the lenses and 3-inch screen are well-shielded in a drop-proof IP54 enclosure. I must admit that I'd have hoped for more modern connectivity.

I have reviewed the E5-XT

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Best thermal-imaging camera for leak detection

This is a pro device for surveyors, so the chances are you'll understand if you'll need it, but if you didn't know about it, isn't it useful to combine your thermal camera and a hygrometer to test air humidity? Yes (well, if you don't mind swapping the sensor in the field).

The benefits of MSX-enhanced IR imagery are clear in any scenario, but especially when you just want to get the job done. Here the extra contrast from the natural light camera combined with the detail (in line with FLIR’s patent) makes identifying moisture problems, air leaks, and insulation issues a relative breeze for anyone in the field.

The 8GB of internal memory will store up to 15,000 images, and their associated hygrometer readings and measurements from the laser measure, the beam of which is directed from a lens near the cameras.

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How thermal-imaging cameras work

For the most part, the best thermal-imaging cameras work like regular ones, except that the image sensor detects invisible IR light and it is translated to a visual “thermogram”. This is what you see through the creature’s perspective views in The Predator and Prey.

Like visual cameras, these images are made of pixels but start at lower resolutions such as 80x60 pixels, or 0.003 megapixels. That sounds limited, but it's enough detail to pick out hotspots in wiring, for example.

See also Best thermal drones

Higher resolutions are always better, allowing you to work at a distance, which is especially important in security and rescue scenarios. Digitally overlaying the thermal image with a high-resolution, visible one can make understanding the picture easier, and many devices on this list do that. (There is a risk here – you need to be confident that the overlay is accurate, something I look at in individual reviews.)

The sensors are also of varying detail (150mK sensitivity means each pixel takes readings to the nearest 0.15˚C, so lower numbers are better). Meanwhile, refresh rates aren’t always high; 9Hz is typical, which is fine for locating hotspots, but not exactly cinematic.

Read more: Best indoor security cameras or Best outdoor security cameras

Thermal imaging works in the dark, or through smoke, but can be fooled by the reflectiveness (emissivity) of a surface. Because IR is part of the electromagnetic spectrum, like visible light, it also has similar properties when it encounters lenses or rain. For professional use, it pays to read up a bit on understanding thermograms, but you’ll understand the basics the moment you power on your thermal camera. Depending on the software, you can also take retrospective measurements from the thermal JPEGs.

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How we test thermal-imaging cameras

I test thermal cameras by using them in day-to-day tasks like inspecting ventilation/insulation, heating equipment (radiators, boilers), plumbing (hot water pipes and taps), and electronics, including gaming devices. I am looking for detail in the image, and the extent to which any optical cameras align with the thermal camera. Latency (the speed of response) and accuracy are also significant issues I test.

We also test any special claims made by the manufacturer about individual products, as well as the overall experience. That means trying processes like downloading images, and what any apps are like (and testing whether they are secure).

Find out more about how we test and review on Digital Camera World

Contact us to discuss your requirements of Infrared Lens for aerospace. Our experienced sales team can help you identify the options that best suit your needs.