The best thermal-imaging cameras allow you to see and measure temperature differences accurately and from a safe distance. They are useful for identifying heat sources in very dark or otherwise obscured places, whether you’re trying to rescue a lost child or to save on your heating bills. Thermal imaging cameras can even help identify infected individuals in a crowd, by picking those that have high feverish temperatures.
An infra-red thermal camera will enable you to explore your world in a whole new way. Beyond the visible spectrum, there is an unseen world of heat radiation. Arty infra-red film photographs aside, the practical uses of the tech traditionally belonged only to military & professional budgets. But now anyone can access thermal imaging. That said, if you simply want to measure temperatures, you may actually want to read our guide to the best infrared thermometers.
For the most part, the cameras work like regular ones, except that image sensor detects invisible IR light and it is translated to a visual “thermogram.” Thermal cameras still have pixels, but starting at lower resolutions (e.g. 80x60 pixels, or 0.003 megapixels). This is enough detail to pick out hotspots in wiring. Higher resolutions are always better, allowing you to work at a distance, as 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.)
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, while it pays to remember that refresh rates aren’t always high; 9Hz is typical. Again fine for locating hotspots, but not exactly cinematic.
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 when you power-on your thermal camera. Depending on the software, you can also take retrospective measurements from the thermal JPEGs.
Best thermal-imaging cameras in 2022
A scan of this list shows FLIR’s patented MSX technology (which boosts the apparent resolution of even low-end sensors) isn’t cheap, but taking advantage of your phone’s screen helps take the edge off.
Although there is a ruggedized ‘ONE PRO’ model, boosting the resolution to 160 x 120 and providing a host of extra features (manual exposure, multiple measuring zones and sensitive up to 400˚C), the standard version is enough to let you discover and measure the temperature visually. This is useful and endlessly fascinating too.
Both include a timelapse function, limited – and it is limited – by the battery life. Weirdly it uses its own battery, and has an independent power switch, though that does mean that it won’t steal too much power from your precious phone battery. The knob which you might imagine to be a focus wheel actually adjusts the phone connector’s length to match your phone case thickness.
Busy contractors will want a iPhone power bank to keep this running at the least, or to look further down this list, but for the average user this will be plenty to get a few shots or clips via the easy-to-use app. Your phone’s big touch screen is great for taking touch readings or, with the Flir One Pro, setting regions of interest.
This tiny phone add-on provides more resolution and higher sensitivity than the FLIR equivalent (even the Pro one), making it a great choice for contractors, engineers, inspectors looking for that bit more resolution. With adjustable focus, the lens can be set on subjects as far as 550m (1,800ft). That’s not only handy for outdoor pursuits, but allows you to take full advantage of the relatively high resolution to get sharp thermal images at any distance.
While the FLIR One includes a visible light camera (essential to the MSX tech), the Seek CompactPro uses your phone’s camera to provide a split screen picture-by-picture function, which is subject to some parallax issues. On the plus side the 15Hz refresh rate makes for better video (but can raise export issues when leaving the US as it becomes “military grade”). The app can give centre-spot measures, or automatically highlight the hottest and coldest spots in a scene.
With a rugged body that’ll survive a bit of workplace rough-and-tumble, the FLIR C3-X or FLIR C5 are good-looking compact thermal imagers well suited to DIYers and contractors. Both have two cameras, a 5 megapixel optical lens and 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. The visual camera can also provide a picture-in-picture option. Of course the low resolution boosted with visual only works in good light, so a small LED light is provided, but that only offers limited assistance.
Both versions have a 3-inch touchscreen and can store around 500 images onboard to transfer via Micro USB. The ability to type notes in via a touch keyboard can be handy, too.
If you can stretch to it, the C5 model adds more analysis features and Wi-Fi so you can get images to your phone 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. FLIR Tools is available for Windows, iOS and Android, though the Mac version has been discontinued (despite MacBooks appearing in FLIR’s promo shots).
This is an extremely flexible portable thermal camera with excellent resolution, meaning that it is just as useful at night as during the day. While the FLIR C-Series produces useful images in good light via MSX, this camera can do so at any time since it doesn’t rely on visual light to boost its resolution. Combined with its 15Hz refresh rate (most are 9Hz), it can easily be used to spot animals or people in the dark, or through dense foliage, just like the Predator does! There’s also a 300 lumen LED light on should you want to surprise someone you’ve spotted in the dark.
The simple menu system provides access to other useful features too, like Level and Span adjustments (a little like manual exposure, allowing you to isolate a thermal range), and Emissivity adjustments (manual or pre-sets). The fixed-focus camera works between 30cm (12 inches) and 550m (1,800 ft) and the 2.4-inch color screen is protected with Gorilla Glass. The 4GB memory can capture as many images as you’d need to (you can hold the shutter down if you like). For distance temperature readings you can use the 4x digital zoom (though the resolution suffers).
Featuring a laser and a continuous-scanning IR thermometer, this device is a kind of hybrid between a non-contact thermometer and a thermal imaging camera.
The grip shape is ideally suited to tasks like car maintenance since one-handed operation is easy, and the cool bullseye-shaped laser dot makes it simple to direct the point of interest. The 2.4-inch color screen (refreshing at 8.7Hz) provides plenty of confidence that you’re getting the right readings for your work, boosted by the MSX tech for a sharp view.
The generous battery will provide five hours use in the workshop, and charges via the same USB connector which can be used to offload the saved images – up to 50,000 of which will fit on the built in 4GB. The system also allows for emissivity correction (manually or with 4 handy pre-sets), and includes a tripod mount in the bottom of the grip.
Enthusiast mechanics may prefer to hunt down the cheaper TG165, an earlier FLIR product aimed at this category which still features a laser and IR thermometer, while the near-identical TG275 can perceive an even greater temperature range.
The Seek ShotPRO is a compact IR camera which boasts a much better thermal resolution than its immediate competitors but, unlike some other accessibly priced Seek products, also includes the ability to mix visual light. The technology, SeekFusion, allows you to adjust a live overlay with an on-screen slider, a little like changing opacity in Photoshop layers. It lacks the edge-enhancement of FLIR MSX, but on the other hand the greater thermal resolution means that isn’t really needed.
The Short Pro, like the FLIR C3, is capable of Wi-Fi streaming (it partners with a free app called SeekView), though still boasts 4GB memory to capture stills and video. Even without the app, the 3.5-inch touch-screen can be used with the built in analysis tools; you can create up to three boxes and monitor minimum, maximum and average temperature in each. Using the tripod-mount, this can be handy for watching things change over time.
Combining at 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 perhaps a deer – hiding at around 100 yards (91 meters) 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, giving this scope a broad range of security and hobby uses at a relatively accessible price point.
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 cable included (though perhaps wireless transfer would be a nice addition).
With a fixed field of view (20˚), the controls are not challenging – just brightness and the option to switch the color pallete (White Hot, Black Hot, InstAlert, Graded Fire and others); a single button handles recording with a short press for a still and long for video. The 9 Hz refresh rate is fast enough to make hand-holding practical.
CAT mobile phones are designed to take serious abuse - with a construction that means that they can be dropped without having to worry about dents or cracking its Gorilla Glass 6 screen. With IP68 rating it can be submerged in 3m of water without fear of ingress. But this industrial design also comes with some useful additional features that you don't find on a phone – including a very capable thermal imaging camera built on the FLIR 3.5 sensor (160 x 120). This is useful as it’ll reduce the things you need to carry and avoids any connecting with IR cameras via Bluetooth or cables. The phone too is a perfectly serviceable affair with 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 12 megapixel Sony sensor, comes with Android 10 (with 11 promised) and supports the Android Enterprise feature set.
NB. The older CAT S61, still available in places, had a lower resolution IR camera, but offered laser measuring, offering an alternative with even more flexibility.
This 5G phone is built to handle temperature extremes and report back; its thermal-imaging camera with an unusually high resolution and frame rate (25fps) as well as the ability to survive in Arctic temperatures. The G1 Pro’s styling makes no attempt to hide its rugged nature, using the 23mm thick protective frame to house a 33mm diameter 3.5 watt speaker which can put out 110db. The 8-core system is nothing to write home about, but fast enough on the clean Android 11 supplied, while other useful tools – including fingerprint ID, NFC, Bluetooth 5, 18W wireless charging and a definable side key – are all there. Ruggedization hasn’t stopped microSD cards or 3.5mm headphones being used if required, either.
FLIR’s rugged E-series, of which the E8-XT is the top of the line, is a great professional tool offering 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 the 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 and easy to use (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 an IP54 enclosure which can survive a drop.
The FLIR Breach PTQ136 is the ideal device for law enforcement; while some monoculars are built with hunters or wildlife enthusiasts in mind, the PTQ136 is smaller, lighter and can be worn as a helmet mount to make it easier to tail subjects (perhaps that should that be ‘suspects’) hands-free.
The device also features on-board video recording and image capture, useful in evidence gathering or for filmmakers. All users will appreciate the smooth experience that is the 60Hz refresh rate, making wearing on a helmet rail practical without inducing wooziness (though of course this tech does result in the user looking a little like the Terminator).
Recording (sadly at only 30Hz) is to built-in memory, sufficient for 2.5 hours or 1,000 images, which are then downloaded via USB-C. The weatherproofing does make the buttons and focus very stiff, but the device will certainly survive a few knocks.
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 by 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).
The IR202 is an ideal home inspection tool, made extremely portable by its compact design and piggy-backing of the power from the host phone. At 15fps, the imaging is faster than some thermal images, though the 80 x 60 resolution means you’ll want to be relatively near your subject – meaning that hunters might want to look elsewhere for a tool to scan the woods. It is nevertheless a noticeably higher resolution than the device’s immediate predecessor, the IR0102, which had a 32 x 32 pixel resolution.
As a low-priced device, adding this to your toolkit is a lot less painful than some of the devices on this list, and with fuel prices headed up and up, locating leaks (an ideal task for this adapter) could cover the cost surprisingly soon.
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