Science

The Seek Thermal Infrared Camera for iPhone and Android

I think that at some point in the future, smart phones will have a built in infrared camera. But for now, you are going to have to use an IR camera add on. Here's what you can do with the Seek Thermal infrared camera for iPhone and Android.
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Rhett Allain

I think that at some point in the future, smart phones will have a built in infrared camera. But for now, you are going to have to use an IR camera add on. This is the Seek Thermal infrared camera. What do I think about it? Let's find out.

An Infrared Review

But what does an IR camera do? What can you use it for? Here is a more detailed overview of the physics of infrared light, but I will give you the short version.

  • Solid objects produce electromagnetic radiation. We like to call this stuff "light" (not to be confused with visible light).
  • When objects increase in temperature, two things happen. First, they produce more light. Second, the wavelength of light gets shorter. Note that they don't just produce one wavelength, but in general the hotter the object the shorter the wavelength.
  • If you look at the wavelength of light (technically, the wavelength of the highest intensity light), you can get an estimate for the temperature of that object.

The best example is your stove element. Before you turn it on, it is room temperature and produces light. Just about all of this light from the element has a wavelength that is much too large for your human eyes to detect. Instead, you see the element because light reflects off the surface and enters your eye. If you turn on the element, it starts to get hot. Eventually, it will get so hot that you can see the light emitted since the wavelength is short enough to be in the visible spectrum.

So the infrared camera take the light that you can't see and displays a false color image where different colors correspond to different temperatures (mostly).

Seek Thermal Details

The Seek Thermal camera is a small device that you plug into your phone. Here is the version that works on iPhones with a lightning connector (so anything from iPhone 5 to current).

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Once it's on your phone, it looks like this:

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Once the camera is attached, you just open the Seek Thermal app and you are good to go. The app has 4 modes:

  • Camera mode. You can capture video or images of what the camera sees and of course you can change the color scheme (so that different colors represent different temperatures). The images are 206 x 156.
  • Temperature mode. Here the camera will give an estimated temperature for a location in the middle of the image.
  • High/Low mode. In this case, the temperature spot will jump either to the hottest or coldest location in the field of view.
  • Threshold mode. In this mode, you can set the camera to only display object above, below or at a particular temperature.

For the temperature readings, the sensor can detect values from -40°C to 330°C. Oh, a quick reminder about emissivity. The IR camera can "see" things through two different mechanisms. It could see the light that an object emits from it's temperature (this is what you want). However, it could also "see" things because of reflected IR light. Different materials reflect more IR light, this reflection is expressed with the emissivity coefficient. A coefficient of 1.0 would mean that no IR light is reflected and a 0 would be an object that reflects all IR light.

You can set the emissivity in the app to match the material you are trying to measure. Here's what that looks like in the iOS version of the app.

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But wait! There is one other mode - Thermal+. In this mode, the app uses both the IR camera and the iPhone's built in camera. This way you can switch back and forth between visible and IR images.

Thermal+ mode. I hope this is clear that it is an image of my laptop.

Since the visible and IR cameras are on opposite sides of the phone, you can get some parallax. Still, it could be a useful feature.

Playing With the Seek Thermal

I've had the chance to carry this IR camera around for a while, I like it. Here are some pictures.

Actually, that's a video. Here are some images.

On the left, ice. On the right, ice with salt.
This is a jumper cable connecting two cars. While the one car is charging, the cable gets warm (current flowing).
The moon.
Two cars in a garage. One of them just arrived. Guess which one.

Here are some thoughts about the camera.

  • Clearly you aren't going to leave this camera attached to your phone the whole time. However, the device is small enough that you can easily keep it in your pocket. It also comes with a small little plastic case so that it won't get damaged.
  • I find that the image quality is pretty nice. It is comparable to stand alone IR camera that I have used before. Of course, the big benefit of having this on your phone is that you can upload the images right away. Also, the stand alone unit didn't record video.
  • When you plug the Seek Thermal into the lightning port on your phone, you can't charge your phone. This seems obvious, but it would be very awesome if there was a female lightning port on the other side of the Seek Thermal camera so that you could do more stuff while using the IR camera.
  • Having an IR camera with you (or easily accessible) is like carrying around duck tape (not duct tape). You never know when it's going to come in handy, but when it does, you are very happy.

Overall, I like this camera. More important: I like having access to a thermal camera at just about any time I might need it.

Seek Thermal vs. FLIR One.

I was going to write a post just looking at the Seek Thermal unit. However, since I previously looked at the FLIR One I guess everyone wants a comparison. Here you go.

  • Resolution: The Seek Thermal has a higher resolution camera at 206x156 compared to FLIR One at 80x60.
  • Temperature Range: The Seek Thermal can measure from -40 to 330°C and the FLIR One is 0-100°C.
  • Calibration: In order to measure temperature, the Seek Thermal automatically closes the shutter for calibration. This must be done manually on the FLIR One.
  • Visible Images: The Seek Thermal has the Thermal+ mode (shown above). The FLIR one has a built in visible image camera and displays an image that combines both the IR and visible camera so that you can see more detail in the images.
  • Battery: Seek Thermal doesn't have a battery, the FLIR One has a built in battery but it is only used for the camera (you can't use it to charge your crappy iPhone battery).
  • Price: FLIR One is $349 and the Seek Thermal is $199.

So, which one is better? The FLIR One seems more polished, but it is also bulkier and more expensive. If you just need an IR camera, the Seek Thermal is cheaper and will get the job done (at a higher resolution). If you have an Android phone, you should probably go with the Seek Thermal (since there isn't a FLIR One for Android). Oh, if you have the iPhone 6 or 6+, the Seek Thermal is your only choice right now since the FLIR One is a case-based camera and only fits the iPhone 5 and 5s. I guess the Seek Thermal would also work on the iPad, but I didn't test this since my iPad is the older kind with the non-lightning connector.

Here is a comparison picture of the same scene with the two different cameras.

FLIR One vs. Seek Thermal.

Should you buy the Seek Thermal? Well, if you need a thermal camera (which I think at some point everyone could use) this is probably the least expensive one you could get. I know I didn't answer the question about whether you should buy one or not.

*Note: Seek Thermal camera unit for review provided by Seek Thermal.