FLIR ONE Gen 3 for iPhone REVIEW

5 min readSep 11, 2018

When I first saw FLIR a few years ago I was pretty impressed. I thought, “Wow, this could really be a handy device.” But would it work as advertised or would it be a product you find in the ‘As Seen on TV’ aisle at your local grocery store? That might be a bit of a harsh analysis but I really didn’t know what to expect from the FLIR ONE. I was truly interested in checking it out. Being a homeowner I knew that I would have plenty of use for a device like the FLIR ONE Gen 3 for iPhone and being a tech reviewer I would have even more daily use for this device when reviewing products that produce heat. So, for the past few weeks, I’ve been testing out the FLIR ONE Gen 3 for iOS and I’m excited to discuss it now.


“There’s an invisible world right next to the one you see every day, just waiting for you to explore it with the FLIR ONE.” This is how FLIR starts out the description page for the device. The idea is that the thermal imaging camera will give you a whole new view of the world around you. It’s a small attachment that connects to your smartphone via the Lightning port (for Apple users). The FLIR ONE app requires a sign in (username/password), but this grants your access to your warranty and latest updates from FLIR. FLIR keeps things simple by stating that the FLIR ONE can be used by DIY’ers, outdoor adventurers, or just a regular user that wants to discover more of the world around you.


  • Scene Dynamic Range: -20 °C — 120 °C
  • Spot Meter: Off / °C / °F. Resolution 0.1°C / 0.1°F
  • Dimensions (H x W x D): 34 x 67 x 14mm (1.3 x 2.6 x 0.6in)
  • Phone: iOS
  • Adjustable MSX distance: 0.3m — Infinity
  • Capture modes: Video, Still image, Time lapse
  • File Formats: Still images — radiometric jpeg Video — MPEG-4 (file format MOV (iOS), MP4 (Android))
  • Palette: Gray (white hot), Hottest, Coldest, Iron, Rainbow, Contrast, Arctic, Lava and Wheel.
  • Video and Still Image Display/Capture: Saved as 1440×1080
  • Emissivity Settings: Matte: 95%, Semi-Matte: 80%, Semi-Glossy: 60%, Glossy: 30% Reflected background temperature is 22°C
  • Mechanical shock: Drop from 1.5m
  • Operating Temperature: 0 °C — 35 °C (32°F — 95°F), battery charging 0 °C — 30 °C (32°F — 86°F)
  • Focus: Fixed 15cm — Infinity
  • Frame Rate: 8.7Hz
  • HFOV/VFOV: 50° ± 1° / 38° ± 1°
  • Shutter: Automatic/Manual
  • Thermal Resolution: 80×60
  • Thermal Sensor: Pixel size 17µm, 8–14µm spectral range
  • Visual Resolution: 1440×1080


The FLIR ONE comes in a well-branded box with an image of the product printed on the front. Some basic details are outlined on the packaging but nothing too detailed. When you open the box you will find the FLIR ONE device, its USB-C charging cable, a quick start guide, and a travel case for it. As compact as the FLIR is, I was very happy to see that a case was included for it. It takes about 40 minutes to charge the device using its USB-C cable. Once it’s done, you can plug it into your phone using the Lightning port. In order to use the FLIR ONE, you must download the free app from the App Store. This app is an imaging app and if you are used to using a photography app of any kind, it’s fairly intuitive.

The FLIR ONE is basically just a camera attachment for your phone. Once you understand that, it’s quite easy to use. You simply point the camera on the FLIR to the subject you want to check and capture a thermal image of that object. The temperature is called out on the image and you can easily see the hot spots indicated by orange/red colors on the image.

As I mentioned above, one of my main uses of the FLIR ONE has to do with product testing and how heat collects on certain devices. Until I acquired the FLIR ONE, I had been using an infrared thermometer. In my daily use with the FLIR ONE, I found it to work just as well as the infrared thermometer to get the heat rating on devices I had been reviewing. Because it’s not just a beam of red light but a camera I also could see where the heat was coming from in the images. This makes for comparing products invaluable to me. The FLIR ONE has also been an amazing tool for me to find the cold spots in my home that might need more of an insolation barrier between the inside and outside of my home.


While I love my FLIR ONE and think it’s been an extremely helpful tool for me, I also find the iOS app to be a bit buggy. Sometimes it freezes for a bit while using the camera and other times it freezes all together where I have to power the device off, force quit the app, and start over. I don’t have any idea what the cause of this is but even with this two software hiccups that I’ve experienced I could not find a reason for someone not to purchase it. This is an amazing tool that is super compact and as long as Apple continues to make iPhones with the Lightning port this will always be with me.

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Originally published at on September 11, 2018.




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