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FLIR ThermoSight Pro PTS Series: Thermal Optics for Hog & Predator Hunting

FLIR ThermoSight Pro PTS Series: Thermal Optics for Hog & Predator Hunting

You may not immediately recognize the FLIR name, but you're familiar with the company's work. FLIR is a leader in world-class thermal imaging, and their products are used for an array of applications too numerous to list. When the Deepwater Horizon oil spill occurred in 2010, FLIR thermal imagers were used to detect oil in the Gulf and expedite the cleanup process. Boston Marathon bomber Dzokhar Tsarnaev was located while hiding under a tarp using a FLIR thermal imaging camera mounted on a police helicopter. In the arctic, petroleum companies use FLIR thermal imaging to identify polar bear dens before drilling for oil. In large and small ways, FLIR's thermal is changing the world in which we live.

FLIR Thermosight PTS233

That technology is also making its way into the hunting realm. Recently, FLIR unveiled their new ThermoSight Pro PTS Series imaging sight (starting at $2,199), a product family that mounts directly on your firearm. Thermal technology allows these sights to work equally well day or night, making them a true 24-hour sighting solution that's perfectly suited for hog and predator hunters. There are currently three different Pro Series thermal sight options, the PTS233, which offers 1.5x optical magnification, the PTS536 with 4x optical magnification and the line-topping PTS736 with 6x optical magnification.

FLIR Thermosight PTS536

At the heart of these new optics is FLIR's new Boson longwave infrared (LWIR) thermal camera core. Just as the technology that powers our cell phones, computers and digital cameras has improved over the last several years so has thermal imaging technology, and the Boson core leads the pack. It's lighter than previous cores, weighing as little as 7.5 grams, and measures just under five cubic centimeters in size without the lens. But despite it's compact size the Boson core packs more tech in a tiny package than previous units, and it does so at a remarkably affordable price.

There are several factors that play into a thermal device's image quality, and the first of those is resolution. More detector elements a thermal camera has the more energy the unit gathers, and the result is improved resolution and a clearer image.

With higher resolution and multiple lens options for a narrow to wide field of view (important for hunters) and you'll be able to identify objects more clearly at any distance. Whereas some thermal units only offer a resolution of 160x120, the Boson core is available with either 320x256 or 640x512 resolution, and that equates to crisper, sharper images with a wider field of view and better detection at extended ranges.

FLIR Thermosight PTS736

Pixel pitch is another key element in thermal image quality, and the lower the pitch in microns the better the image detail. Cameras with a 17-micron pitch can detect a person from 22 percent farther away than a standard 25-micron camera. The new Boson core offers an impressive 12-micron pitch, which results in excellent resolution even at long distances. The Pro Series weapons sight offer better resolution than larger thermal devices from a decade ago at a fraction of the cost.


How does this translate into real-world hunting situations? In short, LWIR technology detects thermal energy, and everything on earth emits thermal energy — even ice. Living things generate higher levels of thermal energy than their surroundings, and FLIR's optics are capable of detecting changes in thermal energy down to .09 degrees Fahrenheit. Even in isothermic environments (where temperatures are the same, such as when the air temperature is the same as the temperature of the skin) thermal imaging can detect living organisms because of an increased rate of emissivity, or the ratio of energy emitted from a surface. That means in total darkness, through objects like smoke, light fog, or vegetation, heat-producing organisms are visible to thermal imagers.

Having that type of technology is invaluable when hunting at night. With a Pro Series weapon sight mounted on a rifle a hunter can see the heat signature of an approaching pig or coyote even in complete darkness and through light vegetation from hundreds of yards away — all without the use of illumination. Additionally, all the Pro Series optics from FLIR offer a 60Hz framerate for smoother, faster image acquisition, a key feature when scanning for targets. In addition to their optical magnification, all three Pro Series options offer 1x, 2x, and 4x digital zoom and onboard video and photo capabilities so you can internally record up to 2 ½ hours of video or 1,000 still images. There's even a recoil-operated video feature that allows you to record video before and after the shot without touching a single button. Talk about high-tech.


The Pro Series family is loaded with additional features that make them ideal for hunting. All Pro Series PTS weapon sights are built from rugged aluminum alloy that can withstand abuse in the field, and all of these sights operate using two affordable and widely available CR123A 3-volt lithium batteries with a battery life of up to four hours of continuous use. There are seven separate color palettes, five reticle color options and six different reticle configurations from which to choose (including 4 MOA dot, line dot, and traditional crosshairs among others), and you can toggle through the options using the optics-mounted buttons. Optics lengths vary from 8.7 inches long to 11.1 inches, and weights range from 1.4 to 2.1 pounds depending on model, which makes this a compact, lightweight weapon sight. An adjustable dual-throw picatinny rail mount is included with each unit, so you can have your Pro Series PTS thermal sight on (or off) your rifle in minutes. And since the reticles are digital there's no risk of losing zero.

In the Pit

Arizona's Gunsite Academy has dozens of shooting ranges, but none are like the Donga. The Donga range is a narrow washout with steep sides fifteen feet or higher, and the shooter is forced to follow the narrow, winding trail until the range opens up into a wide creek bed.


I started through the course armed with a Ruger PC Carbine equipped with a Pro Series PTS233 sight, and after rounding the first bend I saw, through a dried tangle of brush that had tumbled down one of the steep sides, the figure of a coyote through my FLIR. I centered the post and line crosshair just behind the shoulder and fired, hearing the audible clink! of the Hornady bullet striking steel.

FLIR had set up the test course using thermal targets which reflect sunlight and generate a lifelike thermal image of a hog or coyote. And, having used other thermal optics and having actually seen both animals in darkness I was surprised by how lifelike the targets were. I wanted to swap palettes and reticles to a black hot image and a standard crosshair, and I did so quickly on the PTS223. Then it was around the corner where I found a hog hiding in the shade 50 yards away through the thermal. I fired a shot, heard the steel clank, and continued down the Donga course until I'd shot every thermal target on the range. I'd also become familiar with the capabilities of the PTS233, and I was impressed by what this optic had to offer — especially at its asking price.

Affordable is a relative term, but there's no way the average working-class hunter could have dreamt of mounting a thermal optic on their rifle a decade ago without mortgaging their home to do so. FLIR has changed that, and it's truly impressive what the new Pro Series thermal optics bring to the hunting universe. If you hunt hogs or predators at night these scopes are incredibly effective, they're also fun to use and, after a little bit of practice, the controls become quite intuitive. Indeed, FLIR is changing the way that we see the world, and that now includes the way that we hunt.

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