Volume: 16 | Back to issueSubscribe Now
feature By: Patrick Meitin | March, 18
Steven Tisdale eased the truck onto a commanding knoll by feel and familiarity. We stepped out to survey a series of canyon heads choked with the usual assortment of West Texas’ Caprock Escarpment mesquite, hackberry, blueberry juniper and prickly pear, though none was visible at the moment. The countryside was as black as the inside of a crow. I scanned a brushy draw through a Trijicon IR-Hunter thermal imaging scope only briefly before spotting movement.
“Got something,” I said. I flicked on a green-hued light to avoid rattlers and cactus and marched toward the suspicious shape in a brushy draw well below us. At 80 yards that something turned into a white-tailed deer; quite remarkable for being discovered at 300 yards, completely enveloped by brush. I could actually detect game more easily in black darkness with the thermal imaging scope sitting atop the Alexander Arms AWS 6.5 Grendel than if I had been glassing in broad daylight. It was just a bit spooky.
Inspecting another draw spilling from a field edge a half mile away (a place where we had discovered hogs during previous forays), I found what we were looking for. “Absolutely no doubt,” I said. “Those are hogs, and a mob of them.” My father, with his bad knees, elected to stay put and seek closer targets, he and Steven scanned with their own thermal scopes; a FLIR RS32 4-16x sitting atop my father’s custom-built 6.8 Remington SPC, and Steven holding a SIG Sauer M400 .223 Remington that included a SIG ECHO1 Thermal Imaging Reflex Sight.
I understood hogs can be pretty nonchalant when approached in darkness, but also knew they would not tolerate receiving a nose full of human stink. There was some skirting to conduct. This took time, but after circling I easily relocated the herd, amazed anew at my ability to “see through” the brush. I took a mental note: That same ability could come back to haunt me when shooting commenced. Thermal imaging easily reaches through brush . . . bullets do not. Though the Trijicon IR-Hunter scope and streamlined 6.5mm bullets would easily allow 300-yard-plus lethality, I needed to get close.
I eased ahead with the assistance of a TRUGLO TRU-Point laser/light combo clamped to one of the rifle’s copious Picatinny rails, pausing at intervals to keep tabs on the milling hogs. Several appeared monstrous, and occasionally they fought viciously. I guessed a “hot” sow was among the herd. These were the type of boars that generally turned “vampirish” with the very hint of daylight.
I eased within perhaps 90 yards (difficult to know for certain in the dark, though I could have taken the time to employ the scope’s Stadiametric Rangefinder Technology had I not been so impatient to close the deal), earmarking the biggest boar. In all that excitement I also failed to recall the IR-Hunter’s imaging/video capabilities, something I regretted only after the dust settled. The big boar cleared the brush and it was time to put this outfit to work.
It would have to be an off-hand shot. I fought to steady the Thermal Combat Reticle (TCR), settling for just a moment and finishing the trigger squeeze, a Hornady 129-grain SST bullet rolling the behemoth on impact. The situation instantly turned more interesting. I found another big boar making haste out of the draw. Swinging onto its shoulder, the AR barked and I noted the white-hot impact just behind its hams. Swinging to the boar’s nose, pressing the trigger, I saw it roll like a head-shot rabbit receiving a load of No. 4s.
I heard grunting closing in quickly from behind and spun to discover a 200-pound sow and gaggle of 100-pounders bearing down, seeking escape down the very trail I occupied. The sow filled the scope and I jerked the trigger, hitting the ground before its face but coaxing a more beneficial route. Allowing a little space to develop between us, I swung the rifle to its nose and rolled the sow at 60 yards.
The magazine held six more rounds, and hogs were still swirling around me, but I deemed that quite enough for the moment. The first boar still thrashed and grunted, apparently spine shot, so I quickly followed the TRUGLO light to the scene, flicked on the laser and gave the pig a final shot. I felt as if I had been playing the most exciting video game of my life.
While admitting the idea of thermal imaging had long held appeal, it intimidated me just a bit. I can barely operate a cell phone on those rare occasions when forced to carry one while traveling. I’m lucky to live where cell coverage is spotty at best so have largely avoided the entire imposition. With electronics, I sometimes get the feeling engineers are more intent on showing the world how clever they are than providing real function.
I recognized the needed push to overcome these apprehensions while pounding out a varmint/predator-shooting book. Because it was suddenly all the rage, I included an entire chapter on feral hog hunting (though I killed my first 30-some years ago), with a heavy emphasis on all that is new and interesting with this ever-expanding opportunity. Naturally, hunting at nighttime using thermal imaging optics would have to be thoroughly investigated, as spotlighting, even night-vision scopes, are more or less old news.
There seems to be some confusion regarding the latter. Night vision amplifies available starlight or moonlight and transforms it into a green hue visible to human eyes, and projected infrared (IR) light is used during the darkest overcast or foggy nights to covertly penetrate blackness. That “projected” light makes night vision illegal in some states. Thermal imaging is not night vision. In the simplest terms possible, thermal imaging units are cameras optimized to detect IR heat frequencies.
Human eyes perceive limited wavelengths known as – imagine this – “visible light.” This is only a fraction of the bandwidth of electromagnetic energy occurring in our universe. Beyond the red/orange frequencies found at one extreme of the visible spectrum (blue/violet opposite) is IR light. Infrared isn’t visible to mammalian eyes but is felt as heat. Thermal imagers capture this heat and use microprocessors to translate it into discernible images. Technically, you are seeing only an interpretation on an LCD or OLED screen. Since thermal optics project no artificial light, they’re often legal where night-vision units projecting IR light are not, though such technology hasn’t been specifically addressed in some states and regulations are sometimes murky.
These are not blobbed images as portrayed in the movie Predator. Quality thermal optics provide sharp, crisp images with impressive detail. In relation to shy predators such as coyotes and invasive species like wild boars, they allow a hunter to own the night.
An obvious drawback is cost. Decent thermal imaging scopes start at $3,000. Thermal technology depends on the silicon-like element germanium. Germanium lenses focus thermal energy, which then hits a focal plane array (FPA) using a series of registers generating electrical impulses. These impulses are translated into video pixels and displayed on a crosshair-equipped screen for viewing/aiming/capture. Greater resolution and larger lenses obviously translate into more detailed video readout, but also higher prices. Germanium and advanced microcircuitry is pricey, and then there is the added problem of manufacturers not knowing if a particular FPA is operational until final assembly. This leads to a certain degree of rejection and higher manufacturing overhead costs. Like other cutting-edge technology, thermal imaging is evolving quickly, demand is increasing, so costs are slowly easing.
Texas and its plethora of largely despised hogs allowed us to put three thermal units through their paces: Trijicon’s IR-Hunter MK3-60mm (MSRP $8,999) was the most expensive and most advanced test unit; FLIR’s ThermoSight R-Series RS32 1.25-5x (MSRP $3,999) is a solid midpriced scope, and the “modestly-priced” SIG Sauer Electro-Optics ECHO1 Thermal Reflex Sight (MSRP $2,999) covered a cross-section of performance levels.
Trijicon’s IR-Hunter MK3-60mm (trijicon.com) with 4.5x optical/36x digital zoom and 7-degree field of view includes industry-leading 12 micron, uncooled 640x480 VOx (Vanadium Oxide) thermal sensor and digital OLED display technology for superior image quality, and cutting-edge microprocessors for ultra-fast frame rates and lag-free viewing, which made those running shots in Texas possible. The 12-micron technology produces marked image quality and 42 percent more magnification than typical 17 micron systems with similar optical components. MaxPol Technology allows seven polarity modes (three each white- and black-hot, and Edge Detect Technology designed to preserve night vision through lower display brightness).
It includes Stadiametric Rangefinder Technology with range readout display, automatic Digital Focus Control, Enhanced Target Recognition (ETR) concentrating processing power on the target area for more detail and less “washout,” and 8x E-Zoom with first-focal-plane-type reticle viewing. It includes three reticle styles, including Thermal Subtension for longer shots, Thermal Combat with 36 MOA width/height center crosshairs and Thermal Dot with 100:1 spacing. The IR-Hunter is built to MIL-STD-810G specifications to withstand extreme temperatures, vibrations and shock, all sealed inside 6061-T6 aluminum. It weighs 37 ounces, includes 27mm eye relief and features -40 to +55 Celsius operating capabilities. A basic on/off switch and three tactical turrets offer simple, highly-intuitive operation. The IR-Hunter attaches to MIL-STD 1913 Picatinny rails via a dual-lever LaRue system, is powered by three CR123 lithium batteries and is image/video capable.
FLIR’s ThermoSight R-Series RS32 1.25-5x (flir.com) is one of the most affordable units in its performance class and is compact and easy to use. It includes auto image optimization, an advanced shock reduction system able to handle AR semiautomatic rifles chambered for cartridges up to the .308 Winchester/5.56, 3 inches of eye relief and multiple reticle options/colors. Rubber armoring covers the entire scope, which is water resistant for up to 30 minutes in 3 feet of water. The RS32 operates at 320x240 on a VOx FPA at a frame rate of 60 Hz, so is suited to moving targets. It provides a 9-degree field of view and fixed focus.
The 23-ounce unit is image/video capable and includes electronic zoom to 4x. Images are viewed on an Active Matrix LCD; reticles are programmable for duplex, fine duplex or German No. 4 and in black, white, red or green through a simple four-button interface (power/calibration, zoom-in/navigation, main menu, zoom-out/menu navigation). It operates in temperatures from -20 to +50 C. Its internal lithium-ion battery allows for up to four hours of use and can be recharged through a USB port.
SIG’s Electro-Optics ECHO1 Thermal Reflex Sight (sigoptics.com) offers a relatively affordable and simple option providing instant target acquisition with complete situational awareness. The reflex design proved efficient while backing up my father with a SIG M400/ECHO1 combination I could shoot effectively, even without establishing a solid cheek weld to the stock. The ECHO1 includes eight display modes and five default reticles (more can be downloaded at SIG’s website), including white- and black-hot. It includes a 206x156 uncooled VOx Bolometer array, 30 Hz frame rate (sometimes resulting in several seconds of image output delay) and an LCD screen with 3.2 or 4.5 degree/1x or 2x field of view.
The unit captures images in single or burst mode. The ECHO1 offers thermal detection to 1,000 yards and target ranging inside 300 yards. It is IPX-6 waterproof and dust tight. Two CR123 batteries power the unit for up to eight hours. Another plus, it weighs only 14.7 ounces and is a compact, 4.3 inches long, 2.6 inches wide and 2.7 inches high. It includes a fully transferable, unlimited lifetime guarantee.
There would be more thermal hog action to come, but none quite so exciting as that first encounter, though I’m not one to complain. When shooting hogs, I’m a happy man making landowners happy by stemming the tide of America’s most troublesome invasive big-game species.
Thermal Imaging Legality
Thermal imaging is not welcomed in the following states: Alabama, Arizona, Delaware, Hawaii, Kansas, Minnesota, Missouri, New Mexico, North Dakota, Oklahoma, Pennsylvania, Rhode Island, South Dakota and Tennessee.