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Seek Thermal Camera review: Smartphone thermal vision in a tiny package

This tiny smartphone camera attachment can help you see in the dark and get a thermal snapshot of your environment.

Sarah Mitroff Managing Editor
Sarah Mitroff is a Managing Editor for CNET, overseeing our health, fitness and wellness section. Throughout her career, she's written about mobile tech, consumer tech, business and startups for Wired, MacWorld, PCWorld, and VentureBeat.
Expertise Tech | Health | Lifestyle
Sarah Mitroff
7 min read

Seek Thermal gives you the thermal technology that was once only available for the military and other professionals. It's a tiny camera that attaches to your smartphone so you can get a thermal image of anything around you, showing you a temperature snapshot of your environment.


Seek Thermal Camera

The Good

Seek Thermal's tiny infrared camera is easy to carry around and quickly detects the temperatures of anything around you.

The Bad

At $250, the camera attachment is expensive. The images can be grainy, especially if you move the camera too quickly while shooting.

The Bottom Line

Best for DIYers and outdoor enthusiasts, Seek Thermal is a steep investment that pays off with its versatility.

There are plenty of awesome real-world uses for Seek. For DIY and home-repair enthusiasts, the camera can help you see problems inside pipes or see where heat is escaping from around windows or doors. Home cooks can use it to check out their grill's hot and cool spots. Seek is also useful for home security, to see if any unwanted animals or humans are getting into your back yard at night.

At $250, the price is a bit steep, but Seek's versatility makes up for it. Though I wouldn't buy this device just for entertainment, it was very fun to review it because the images you can capture are just plain cool. It's worth noting that professional thermal-imaging tech can cost thousands of dollars, so the Seek is one of the first systems to make this kind of gear more accessible to the masses.

Seek Thermal can see the unseen (pictures)

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The Seek camera

The Seek Thermal system includes a camera attachment for your Android or iOS device and an app that shows what the camera captures. I'll talk about the camera first.

Seek sells two smartphone camera attachments, the $250 Thermal camera and the $300 Thermal Xtra Range (XR), both available for iOS or Android devices. The difference between the two is that the XR can see objects twice as far as the original camera, with the same clarity and the XR has a manual focus feature. For the iPhone, you need to have a Lightning connector and iOS 7 or 8. For Android, you just need to run Jelly Bean 4.3.1 or later. For this review, I tested the original model Android camera and app.

The Seek camera is tiny and plugs right into your smartphone. Josh Miller/CNET

Seek's original thermal camera is tiny, about 1.6 inches long, 0.8 inch tall and 0.6 inch thick and it weighs just 0.5 ounce (14 grams). The chalcogenide lens is offset to the left side and on the right is the connector that you plug into your phone's Micro-USB port. Its tiny size makes it easy to slip into a pocket, but it also means that it's easy to lose it. And if you're spending $250 on it, you don't want to do that.

Thankfully, Seek also includes a well-made carrying case with a soft rubber interior that keeps the camera safe when you're not using it. It also has a loop on one side so that you can attach the case to a keychain or hang it from a workbench. The snap clasp is strong and sturdy so that it won't unlatch in your bag.

Once you've installed the Seek Thermal app (more about that below), using the camera is as simple as plugging it into your phone. The app will launch automatically and on Android you may need to authorize it to communicate with the camera. It's an easy setup that takes just a few seconds each time you want to use the Seek.

Seeing temperatures

The Seek camera works in daylight or at night, basically in any light level, because it doesn't need visual light. Instead, it picks up the infrared waves that everything -- whether it's living or not -- emits. We can't see those waves with our naked eyes, so Seek turns those waves into a visual image, using color. Those IR waves can be used to determine temperature variations around you, so the colors you see with the Seek correspond to different temperatures around you. The effect is really neat to look at, and useful for seeing things normally hidden from our sight.

Seek relies on a tiny sensor chip and a software algorithm to create these thermal images. It captures 32,000 pixels with every shot and each pixel takes a different temperature measurement to create the whole photo or video. The camera can detect temperatures from -40 degrees Fahrenheit to 626 degrees Fahrenheit (-40 degrees Celsius to 330 degrees Celsius), which should fit all of your thermal needs.

A thermal selfie taken with the Seek. Sarah Mitroff/CNET

The photos and video that the Seek camera take aren't high-res by a long shot, at just 206 by 156 pixels. However, you can still make out some detail, especially if you hold the camera still for a few seconds before you snap a photo, so the lens can calibrate. In the test shots I took, most were a bit blurry, but in several I could capture smaller, identifying details. You can use the camera to see a thermal image in real time on your phone's screen, or take photos and video to look at later.

The camera uses an automatic black body shutter to keep the lens calibrated, and it makes a soft clicking noise that you can hear every few seconds. That shutter is different than the onscreen shutter you use to capture a still photo in the app, and in fact, you can't control the black body shutter at all; it's designed to run on its own.

Seek works best when you hold the camera still, whether you're taking photos or video. I found that if I moved the lens around too much, there was significant ghosting, meaning the thermal image would linger on my phone's screen after I pointed it at something new until the shutter clicked again. It takes a few seconds for the lens to focus on a new subject, so you need to be a bit patient when using the camera. I also found that the camera works better in low lighting because that way the heat from lamps or sunlight won't skew the image.

The mobile app holds the magic

The other half of the Seek Thermal system is the app. This is where you can see the camera's viewfinder, take photos and video and control other camera features.

Without a camera attached, you can see gallery of images you've captured. Once you add the camera, you'll see the viewfinder immediately, which works just like your phone's typical camera viewfinder -- just point the lens at something to see the image.

While the app looks bare-bones, it's actually full of a few features to customize what you see with the camera. First, you can adjust the color palettes that the camera displays, from black-and-white to much richer color choices. I particularly like the navy-to-orange filter called Tyrian and the teal-to-purple filter dubbed Cool.

Next, the camera has different scene modes you control in the app, each giving you a bit of extra information about the thermal image. Spot mode shows you the approximate temperature of whatever is centered in the camera, while High/Low displays the highest and lowest temperatures in the camera's field of view.

In High/Low mode, you see the highest and lowest temperatures in the shot. Here, the dark area is a cup of ice. Sarah Mitroff/CNET

Spot mode shows the temperature of whatever is centered in the frame. This is a toaster oven set to 300 degrees Fahrenheit with the door open. Sarah Mitroff/CNET

Threshold lets you customize the scene, showing only areas that are above or below a certain temperature, which you set in the app. That's helpful if you're searching your back yard for your cat and only want to see spots that are higher than, say, 85 degrees Fahrenheit. There's also a Normal mode, which simply shows the heat variations without anything else on the screen.

Lastly, there's Thermal+ mode, where you can see a split screen from the Seek camera and your phone's main camera together. You can drag the slider on the screen to control how much of each image you see. Because the image is coming from two different cameras, you do lose a bit of the picture in split-screen mode.

Other features in the camera include toggling the aspect ration between 4:3 and 16:9 and switching to video mode, which can use all of the scene modes I mention above. You can also control which temperature metric appears onscreen: Fahrenheit, Celsius or Kelvin.

Who's it for?

The Seek is a really cool system that takes traditionally scientific and professional-grade equipment and brings it to your smartphone. But it's still a niche product that doesn't make sense for everyone to have. If you're still wondering why you would buy something like this, here are a few great uses for a thermal camera like the Seek.

If you're big into DIY and home and car improvement, thermal cameras can help you essentially see through walls and pipes to detect problems. You can check out clogged drains by running hot water through the pipe and checking where it stops, or follow water damage through a wall to find the source. It's also great for checking if hot air is escaping your home, through a window, door jamb or crack.

Thermal cameras are also great for home or personal security. You can see if there's an intruder in your back yard or an animal that shouldn't be there, like an opossum hiding in a shed. Though I might not always carry this around, you could use it in a parking lot late at night to make sure no one is hiding in a car.

Lastly, the Seek is useful for cooking to inspect your grill and even check the level of your propane tank. You can investigate your oven for hot and cold spots, which most ovens have. Heck, you could even use a thermal camera to check if your beer is cold enough to drink.


Expensive, but versatile and downright cool, the Seek Thermal camera is a great little gadget that has seemingly endless uses. It's well-built, with a solid design and a sturdy carrying case and it works great, with a few caveats. There's a small learning curve for the Seek, but once you get the hang of it, you can quickly take thermal images anywhere you go.

While the Seek system is one of the coolest and most useful smartphone accessories I've come across, it's not for everyone. Until the price comes down, you'll want to really consider what you'll use it for before you plop down the $250.

That said, if you're trying to decide between the Seek and it's equally priced competitor, the FLIR One, I would say that the Seek is a better deal because it's compatible with so many devices and can easily switch between phones. The FLIR One is limited because the camera is built into a case that only fits the iPhone, while Seek's camera attachment can work with nearly any device. That makes it the better buy.


Seek Thermal Camera

Score Breakdown

Setup 9Features 8Interface 6Performance 7