Last year, Senior Editor Lee Hutchinson played with the FLIR One, a $349 iPhone case that had two embedded cameras to bring you all the power of Predator in John McTiernan’s 1987 film Predator. That is, the camera took infrared measurements of its surroundings, producing an awesome thermal image that transcended the visible spectrum.

Now FLIR, a military and industrial technology company based outside of Portland, Oregon, has come back with a second version of its consumer-grade product, priced at $249. This next-gen accessory is also called the FLIR One, but this time, the company has eschewed the iPhone case for a dongle that attaches to the bottom of a compatible iOS device via the Lightning port. Better yet, the FLIR One is no longer iOS-exclusive, and an Android-compatible dongle works with a handful of Samsung and Asus phones, as well as the HTC ONE M8 and the LG V400.

On top of that, the company is saying that the long-wave infrared sensor (called the “Lepton Core”) found in the 2015 FLIR One has four times the resolution of the one found in the 2014 FLIR One.

So, we thought we'd try it out again, a year later. If only just so we could stalk around the house making clicky noises and whispering “turn around.”

New Lepton Camera, better than the old Lepton Camera

Specs at a glance: FLIR One Visible light camera VGA (640 × 480), used for MSX blending IR sensor FLIR "Lepton" LWIR (long wave infrared) Temperature sense range -20° to 120° degrees Celsius Thermal variance detection 0.1° Celsius Onboard battery 350mAh Ports MicroUSB (charge only) Size 72 mm x 26 mm x 18 mm Weight 2.75 ounces Supported smartphones A variety of iOS devices and a handful of Android devices Price $249

Like the first generation FLIR One, the new One has two cameras. The first is FLIR's proprietary Lepton Camera, which the company says is “the most compact long-wave infrared sensor available.” This camera detects longer wavelengths in the electromagnetic spectrum given off by infrared radiation, but this generation bumps the resolution of the camera from a fuzzy 80×60 to 160×120. The Lepton can also detect a wider range of temperatures than the old version could—where the first generation could read temperatures between 0 to 100 degrees Celsius, this new version can detect differences in temperature from -20 degrees to 120 degrees Celsius.

Temperature sensitivity, however, is the same as the old version, with the ability to detect 0.1 degree Celsius differences in temperature.

The FLIR One's other camera is a regular VGA “standard camera.” The device takes the picture, and through a process called “MSX Blending,” it extracts detail from the visible light camera and overlays it with the thermal image from the Lepton camera. This is what actually makes sense of the thermal image—without it, you're staring at a bunch of rainbow-colored blobs trying to figure out if any of the information you're seeing is useful.

Although the composite image is still 640×480, the heightened thermal resolution gives the resulting pictures a crisper look.

In the accompanying FLIR One app, you also get a couple of new options—now you can take panoramic shots and create time-lapse videos from within the app. Like before, you can choose the colors you want to indicate relative heat, but we mostly stuck with the default option (as we'll remind you, infrared waves are colorless, so infrared cameras give the wavelengths false colors to show us useful information). Another really cool thing: within the FLIR app's library, you can swipe up on your thermal photos to see the visible light photo without any thermal information. This helps if you have a bunch of photos in low light where MSX Blending may have dropped some key details in combining the thermal image with the VGA image.

Using it

Megan Geuss

Megan Geuss

Megan Geuss

Megan Geuss

FLIR

FLIR

Megan Geuss

Megan Geuss

Megan Geuss

My biggest issue with the FLIR One is that it's pretty dang bulky, and if you don't have an iPhone case with an open bottom, you'll have to take off your case, or use the phone for extended periods without the case, which is less than ideal (yes, I dropped the phone, and yes, I cracked the screen. $109 later...). Of course, solving this problem is easy—get an appropriate iPhone case if you plan to invest $250 in a FLIR One.

Still, phones are bigger and longer (a little bit taller) than ever, and having a dongle that juts out an inch or so from your lightning connector felt precarious. You can't leave the dongle in there and walk around; you have to choose when you want to take some thermal images, and then slide it in and turn it on.

FLIR foresaw this situation, and the new FLIR One comes with a little bumper keyring you can wear around your neck. The problem with this, though, is that it holds the FLIR One in a bit too well, and I often had to use my keys to wedge it out of the death grip that the case had on it.

Although the camera is so tiny for what it is, and any weight it adds is nigh-imperceptible, I wish there had been a better way to use it without making my phone feel like I added a shaky table leaf to an already tight Thanksgiving spread.

Still, the device itself was easy to use once I accounted for how it felt on my phone. You can plug the FLIR One in either direction on Lightning-equipped iOS devices, so I was able to watch what I was filming at all times, whether the object of my infrared gaze was behind me or in front of me. The device contains its own 350mAh battery, which must be charged via a micro-USB port. The FLIR One can not charge or receive charge from the phone it's connected to.

The battery is the only place where FLIR seems to have chosen to downgrade its hardware from the first to the second generation. The first generation FLIR One had a much larger 1400mAh battery. Still, we had pretty good luck with the next-gen FLIR One when it was properly charged, getting anywhere from a couple of days of intermittent use to about an hour of continuous use. Recording video seemed to be a huge battery life suck, as you'd expect. There's no way to tell how much battery life you have left, however, so keeping it charged before you try to spend a couple of hours looking for the cool air leaks in an apartment building is key.

Also, gone are the days of “tuning” the device. In the first generation FLIR One, Lee was prompted to “tune” the sensor every few minutes by holding a switch until the camera had calibrated. Now, that's all done automatically within the sensor (although you can still manually tune the device from within the app if you so choose.)

In the field

Megan Geuss

Megan Geuss

Megan Geuss

Megan Geuss

Megan Geuss

Despite my trouble with the way the thing felt on the phone, playing with an infrared sensor is pretty darn fun. Is it $250 worth of fun? That depends on your budget, but if you were interested in the FLIR One last year but turned off by the $350 price, maybe you're convinced at this price point this time around.

In a meeting with the company, a FLIR representative told us that its aim in building a consumer-focused FLIR is to “bring infrared technology everywhere.” While this has somewhat Orwellian overtones coming from a company that has a tight relationship with the military, for now, FLIR has focused on sponsoring hackathons to build simple and/or fun infrared-based apps. (Cynical Megan wants to say “that's how they reel you in,” but if selfie culture hasn't already ruined today's youth by making privacy a thing of the past, I'm not sure that infrared apps are going to tip the scales in favor of constant surveillance.)



























Anyway, FLIR has been partnering with groups and companies like Owens Corning, which built the “Comfort Tracker” to help people do a home insulation assessment. FLIR also worked with a Dressage rider/veterinarian as well as a former professional rider to develop “InfraHorse,” an app that lets you take a look at your horse to see if it has any “hot spots” that might be causing it pain after a ride. (Check out the Infrahorse Facebook page to see lots of people taking very colorful pictures of unimpressed horses).

In our own use, the FLIR One proved to be the same as it was last year—super interesting, but not a must-have device. I got the most out of the device at night, using it to find my dog in the dark, bush-filled backyard, and I was able to watch my knees cool down in an ice bath after a long run (see video).

It wasn't always perfectly accurate when I had the Spot Meter enabled (which gives you a temperature estimate for the thing you're pointing the FLIR One at). My body sometimes registered as being much colder than it should be, and I drank a beer in a bar that was certainly colder than 50°F. That said, FLIR cautions that a number of external factors could contribute to “off” readings. “The accuracy of the Spot Meter depends on a great many factors, including the distance from the object, the ambient temperature, and the emissivity of the material being observed,” the manual explains. Maybe the glass the beer was in was not perfectly cold, or maybe I had just put on fresh clothes that altered the ambient temperature.

When we first reviewed this product, we wrote that FLIR had made a damned interesting device, and at a price point around $99, that it would be an easy thing to recommend. That analysis still stands, but with the caveat that the FLIR One needs to be easier to either leave on the phone or to get out of the bumper case. And since FLIR has shown that it's not scared to make pretty dramatic design changes, we predict that will be a small hurdle in the future.

The good

Incredibly easy to use and easy to pair with your phone.

Now works with some Android phones.

Thermal imaging is cool and moderately useful in everyday life.

SDK now available, so developers can build their own apps for it.

Considerably cheaper than a more industrial thermal imaging system.

The bad

Difficult to know how much battery life you've got left.

Still $150 too expensive for a device that's not essential to your everyday life.

The ugly

Man is it difficult to get out of its bumper case.

Listing image by Megan Geuss