We can’t see in the dark, and that’s a bad thing. Yes, this is a pretty obvious statement, but that doesn’t make it any less true – or any less of a problem for a prepper. For a big chunk of the day, our vision is seriously reduced by lack of available light.
Sometimes that’s just inconvenient; it’s hard to work in your vegetable plot when you can’t see what you’re doing. Other times it can actually be dangerous.
Night is a time when predators come out, both animal and human. In darkness it’s much easier for them to move into attack range without being detected, or lie in wait to ambush their prey – and the prey they have in mind might be you.
What are you supposed to do, though? Spend all night cowering in your house, hiding from the dark?
Related: How To Hide From Thermal Vision
One solution is to use night vision equipment, but there’s a problem – night vision equipment is expensive. Military-grade systems cost thousands of dollars, and even a basic observation device will usually run to a few hundred.
On top of that, a lot of the cheaper systems are active infrared. They have a built-in IR illuminator that can’t be seen with the naked eye, which lights up the scene for the viewer, but if someone’s hiding behind a bush they’re still hidden.
Night Vision For Your Phone
There’s one affordable device that’s a bit different, though – the FLIR ONE thermal imager. This is a passive infrared system; it picks up the heat emitted by objects, and displays that on a screen.
That means it works even in complete darkness, and doesn’t need an IR illuminator. It can pick up warm objects behind colder ones, as long as the barrier isn’t too solid.
What’s interesting about the FLIR ONE is that the device itself is just a thermal sensor and a battery, in a small package that connects to a smartphone. Its image is displayed on the phone’s screen, which means you get a bigger display than most night vision systems, as well as access to the phone’s other features.
The third-generation FLIR ONE costs around $200 and comes in two versions, for iPhones or Android phones with a USB-C connector. Inside the box is a small zippered case, which contains the imager and a USB-C charging cable.
Meet The FLIR ONE
The imager is extremely small – just 1.3 inches high, as wide as an iPhone and just slightly thicker at 0.6 inches. On top there’s a connector to plug it into the phone; under it is a knob that adjusts the height of the connector to suit phones with or without a case.
On the front are two cameras – one thermal and one visible light. On the bottom is a USB-C port, to charge its internal battery, and an on/off button. It’s solidly built and feels like a quality item.
To use it, the first thing you need to do is fully charge the imager’s internal battery. While you’re doing that, download the free FLIR One app to your phone.
When everything’s ready open the app, plug in the imager then switch it on; after a few seconds the thermal picture will appear on your phone. It’s quick and simple, and also totally reliable.
When I first looked at the FLIR ONE’s thermal image I couldn’t believe how good the resolution was. After a closer look I realized it wasn’t that good; a lot of the detail you’re seeing isn’t from the thermal camera.
It uses the visible light camera to draw an outline, which adds a lot of detail to the image and can be very useful. The problem is that the visible light camera won’t work in complete darkness, and the thermal camera on its own has a much lower resolution.
In fact the resolution of the thermal sensor is just 80×60 pixels. That limits its effective range; at long distances, if a warm object only covers a small part of a pixel, that pixel’s average temperature won’t be different enough to register.
So how far away will it pick up a human or an animal?
Testing Its Performance
I tested the FLIR ONE by taking it into town and observing people in the street – and it worked. Obviously it doesn’t perform like a military surveillance device, or even a $500 thermal hunting scope, but it will easily pick up a person at over 50 feet.
I did notice that the thermal and visible light images don’t line up perfectly, especially at shorter distances, but you can easily work out what you’re seeing.
Related: Camouflage and Concealment: The Art of Staying Hidden
For the next test I headed into the country to photograph some sheep, and this time I covered the visible light camera for most of the shots so the image is thermal-only. As expected, that made the image a lot less detailed – but it did detect a lot of sheep.
There were a bunch of them scattered around the field, and they showed up clearly out to at least 70 feet.
Limitations
What the images don’t show is that there was another group around 300 feet away, and they didn’t show up at all. 
There were some buildings around half a mile away that did show up, and I’m pretty sure that’s because they were big enough to cover at least one whole pixel on the sensor.
So the FLIR ONE has limitations, but it does work. Could you use it for long-range surveillance? No – but could you use it to scan your yard and check for intruders? Yes, definitely.
It takes about 40 minutes to charge the device, and a full charge will keep it running for about an hour.
It isn’t supposed to draw any power from the phone’s battery but I did find that my iPhone ran out of power a little faster; that’s probably because it was constantly showing video, rather than any direct power draw.
It’s quick and easy to take either photos or video with the FLIR ONE app; they get saved to the phone and can be stored or shared as normal.
Is It Worth Buying?
My only real complaint about the FLIR ONE is that it can occasionally fall off the bottom of the phone; there’s nothing holding it in place except the connector.
I’m thinking of designing and 3D printing a new case that will hold the phone with the imager attached, to solve that problem.
Apart from that it’s a surprisingly capable little gadget that will give you a new view of the world at night.
You may also like:
How the Government Shutdown Affects Preppers
The Awesome DIY Device That Turns Air Into Fresh Water! (Video)
I work in pest control and this is excellent for finding bees/yellow jackets in walls.
Where is this manufactured?
I have a hunting Thermal Scope and it was expensive but the device in this story for about $200 sounds like a waste of your money. It can spot a man from about 50 feet is ridiculous. I’m NOT going to stake my life on that. With my and my friends equipment we would spot you and put you down a hundred yards away. This device sounds like something that kids might like playing hide and seek inside your house with the lights off.
Just out of curiosity, Chuck D, and I hope I’m not overstepping; may I ask you when you bought your thermal scope and how much it was at the time. If I’m out of line then it’s none of my business.
Sounds like a device for spotting insulation issues in a house versus surveillance.
Sad part is the illumination from your phone camera is going to give your position away.
Sorry I didn’t get this out sooner, but it’s summer and the really busy time of the year for me. I hope my comments are found to be beneficial to some…
I’m impressed with my weapon mounted variable power thermal scope that operates day/night on a dedicated AR platform. Thermal scope technology has advanced and prices have dropped significantly over the last few years and now offer amazing clarity at lower prices….one can expect significantly better quality than what you see on a phone adapter. Down side is that what I choose several years ago was $1700 new, but there are several manufacturers and the prices vary, so do your own research and find what fits your needs and budget. As you read this, you wonder does this guy have a clue? Let me answer….Yep! I personally have NVG gear including PVS-4, PVS-7 and PVS-14 in addition to the above mentioned thermal scope and they were all a struggle to afford, but do allow side by side comparison, so yes, I do know. Sorry, but decline to go in to additional details of what I have, but reiterate to do your own research and find what fits you needs and budget. God Bless.
Eventually, everything comes down in price, and quality. While I can’t see in the dark like a horse can, I do OK. Still, it would be great to have something like this, if it’s got some quality. niio
Say, Claude, what is up with the website. I have posted on this list two times and neither time did the post show up.
I don’t know if Akismet is blocking web addresses or blocking talking about prices but I am trying to post about a less than one hundred dollar FLIR device that Midwayusa has for sale. Inasmuch as those posts are not appearing, you will have to look up the device yourself. Midway is also offering free shipping for over forty nine dollars orders for a limited time.
What device does Midway have? I checked their website but couldn’t find anything. I have a ATN thermal scope which works great. Helps us keep down the Coyote population we’ve got here in Casa Grande, AZ.
Well, I haven’t figured out whether is is posting dollar amounts or posting a web address but as you can see from my just posted comment, where there is no e mail address nor a dollar amount that it was posted whereas an early post did not appear. Interesting. Hey Claude, what is Akismet blocking, e mail addresses or dollar amounts?
Here are two that I found on Midway’s site:
Truglo Digital Night Vision Monocular Product #: 355553 Our Price:$179.99 $79.99
Stealth Cam X-NVM Digital Night Vision 3x 20mm Monocular IR Filter Black
Product #: 305440 Rated 4 out of 5 stars Our Price: $114.99 $89.99
The eighty dollar one and the ninety dollar one are the sale prices. There were others that were over one hundred dollars that I didn’t gather the info on. I hope this posts
Pretty sure those are just “infra red” viewers not true “thermal” viewers. Not bad options I actually have a similar one, but they still rely on a “light” source vs heat.
Proven fact – Technology gets cheaper as the next version roles out. If you can wait a bit, you won’t have to worry about becoming obsolete or maneuvering to try to trade up. Always remember that you get what you pay for. Buy the best you can afford. It’ll pay back in spades!
I just put in Night Vision in the Midway search block and turned up approximately 20 devices ranging from the eighty dollar device to a six thousand dollar device. I would expect the six thousand dollar device not only to reveal someone within 500 yards but also tell me the sex of the individual and whether he or she was friendly or not; whether armed or not and if they spoke English. I would expect it to have a ray that when activated would render the individual temporarily unconscious so that I could approach without danger. That’s a toy for someone with a lot more bucks than I have.
The reviews of the eighty dollar device indicated that it was not the most powerful FLIR in the catalog but for the price was adequate.
LCC: what, no biography, blood type, what they ate for breakfast? Cheapo pricks! niio 🙂
Sorry, Red, the humor in your post escapes me.
anything that expensive…
I have no interest in being paranoid and whack everyone, even if they are armed and, believe me that in KY, we are all armed, but I now live in suburbia and think this item of Claude’s has a great function for stealthy movement around the dark house and especially the yard or camping site, or a sentry post in the woods for intel gathering! My grand boys would be close up pros with this and unless it’s a military or gang style all out firefight our killing would have to be knives, shotguns, or pistols close in where this item might give us an advantage, even with the cell illumination. If the yard or house intruder is neutralized, I don’ mind executing or having a shoot-out with anyone that’s going to be a loose mouth or an on-going threat!
I absolutely love your site, I’m also into the survival niche.
Lean towards one of your items of course the water Freedom system.
I also fell in love with your night vision items will be looking deeply into him