FLIR Infrared Thermal Night Vision versus Image Intensified Night Vision
At least once a week someone will pick up one of our thermal imagers and say with surprise “Oh, it’s not green inside?” because somewhere along the line they thought all night vision works the same.
There are a number of key differences between the thermal imagers FLIR makes and traditional image-intensified night vision devices (NVDs)
From a technological standpoint there are very different things happening when you run thermals compared to running an NVD. But there’s also some decisions to be made about what might work best for you, depending on what you are asking your equipment to do.
Night vision intensifiers are amplifying the existing light. This means that the filter inside of them is enhancing light that is barely there and filtering it through a series of photon replicating plates to your eye. There’s a lot more going on in there, but the core idea is that an NVD takes what light you have already and makes more of it.
Thermal imagers on the other hand use a microbolometer to detect the infrared radiation emitted by objects around you. When infrared radiation is focused onto the uncooled detector, the heat absorbed causes changes to the electrical properties of the detector material. These changes can be compared to a base value and used to create a thermal image. The key advantage here is that thermals will highlight and differentiate the environment. Rather than simply brightening the image, they are reading the radiation which produces a full spectrum of different heat sources.
At its most basic, Night vision comes in three common generations, with an auto-gating feature that can be applied to any of them.
Similarly, Thermal imagers come in three common resolutions, also with a high refresh-rate feature that can be applied to any of them.
So which is better?
That’s a hard question. Most western militaries issue their soldiers with NVGs of some kind, as the ability to conduct operations at night has proven a major advantage in all our recent conflicts. Thermal units have come down dramatically in price, more than 50% in the past ten years. But they are generally still more expensive than common night vision units.
Gen 1 nightvision may only cost $300, but it borders on being unusuable with its filmy view and limited range. The starting point for a thermal camera is much higher, $1999 for the FLIR PS24 but you get the full functionality of the technology out of the box.
The prices escalate differently between the technologies though. The LS 64 with a 640X512 detector and running at 30hz is only $5999. That’s compared to an autogated PVS-23 Gen 3 night vision device which comes in at a whopping $8599. There is a massive variation between night vision, anywhere from $300 to $9k. A long distance FLIR unit can cost over ten thousand dollars, but the handheld FLIR units are all within $2k-$8k.
Those expensive long distance thermal units do have the benefit of reaching further than any hand held night vision device. A FLIR BTS unit with a 100mm lens can reach out over a kilometer, while most night vision scopes are only 3X or 5X magnification. There’s nothing in the lineup of traditional nightvision devices that will do long range like the BTS units with their telephoto lenses.
Night vision devices are better for the infantry. Because all these units are sensitive to IR light you can use beacons, friendly indicators, and IR lasers for a variety of tools that are only visible to people wearing nightvision. Thermal units only identify heat, so they don’t care which uniform your wearing, but they can pick out a camouflaged person from their surrounding instantly.
FLIR units are also easier to pickup and use. Make sure they’re charged, and that’s pretty much all the maintenance they need. There’s no finicky focusing like the first two generations of NVDs, and no light restrictions at all. This means they also aren’t constrained to night-time activities. As an outdoorsman, FLIR can have multiple roles in your pack: As a scanning tool, as a confirmation tool, and as a night navigation unit.
For anyone hunting or looking to remove varmints, the flexibility of FLIR makes it a superior option to regular nightvision. The Armed Forces keep FLIR options in most vehicles and spotter teams because of its superior ability to isolate potential threats and anything of interest in an environment.
From our experience, and what we’ve learned from different people using different technologies, the FLIR units are preferable for most kinds of work taking place at night. NVDs have a limited role when many people are all wearing NV goggles working together, while a thermal image provides a wider range of information to an individual user. But what do you think? Thermal or NVD? Feel free to comment here, or join the discussion on our Facebook page.
If you’ve made up your mind, and are looking for a thermal unit of your own, you can see our entire FLIR line on OptimumStores.com