Regulations vary by state, but thermal optics are permitted in most locales for hunting predators, hogs and non-game species like raccoons and jackrabbits. (Shutterstock photo)
February 07, 2025
By Andrew McKean
Because of sucking mud, the only way to reach the sounder of pigs across the harvested wheat field was to walk under the moonless Texas sky. Every 100 yards or so, I’d stop to scrape gumbo off my boots and scan the dark field with my thermal monocular.
The feral hogs were still there, shining like lamps in the thermal optic, but slowly feeding away from us. I counted at least 25. Some were large adults but most were suckling pigs, the perfect eating size. As I closed the distance, I switched on the thermal scope atop my AR and whispered to my buddies. I’d take the right-side pigs, and if any from the rest of the sounder came my way, I’d handle them too. By stage-directing our shooting, I hoped to avoid crossing any lines. Shooting at night, it turns out, has its own set of hazards.
When my Pulsar rangefinder told me we were inside 100 yards, the three of us, each with a suppressed rifle mounted to a tall tripod, counted down our volley in a whisper. The next 30 seconds were wild. We killed all but about five of those hogs, and the sound of bullets hitting mud and sowbelly was almost as memorable as watching hogs run and fall in my thermal scope, which creates images out of heat instead of light. Through my scope, I could see my screaming-hot bullet contact fairly-hot hog, and occasionally the resulting impact created a spray of warm blood, rendered phosphorous-white in my thermal. Crazy.
We donated the larger hogs to the farmer who allowed us access and kept the 50-pounders for the barbecue. By the time I fell into bed at 4 a.m., my buddies and I had collectively dispatched 34 hogs and walked more than 4 miles across muddy pastures and fields. A pretty good night in Texas, all made possible by thermal scopes and monoculars that allowed us to literally see into the night.
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That was my first experience hunting with thermals, and it opened my eyes to the possibilities of pursuing not only hogs but coyotes and, where legal, non-game species such as jackrabbits and raccoons. If thermals open up entirely new hunting opportunities, they also have a steep learning curve. Which unit is right for you? How much are you willing to pay for devices that have fairly limited utility? And how can you differentiate different models and brands?
WHERE THERMALS SHINE Most states prohibit the use of thermals for hunting game animals. That makes plenty of sense, since these heat-detecting optics are configured for use at night, long after legal hunting light. A few states allow thermals to be used for game retrieval, and their ability to detect splotches of warm blood and even dead animals that haven’t fully cooled, make them extremely useful retrieval tools.
But thermals are so disruptive, giving hunters such an advantage over wild animals that use the night as their sanctuary, that they push the limits of fair-chase ethics. As a result, some states prohibit hunters from possessing thermals during big-game seasons. Check your state’s regulations carefully to educate yourself on what’s allowed and what’s prohibited.
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Most states allow thermals to be used for predator and feral hog hunting, and it’s calling coyotes at night and scanning fields for pigs where thermals really shine. Coyotes, especially on private land or on blocks of remote public land where they’re not chronically harassed, often come right in to calls at night, thinking that they’re hidden by the dark. Thermal hunters still have to watch their wind and avoid moving or making alarming sounds, but night hunting can put a lot of fur on the ground.
Thermal optics are widely preferred over night vision for hunting since they reveal a heat signature and do not require any ambient light to produce an image of the target. (Photo courtesy of Pulsar USA) If you’re already wincing at the high price of thermal devices, you won’t want to hear this, but in order to maximize your success with thermals, you really need two: a dedicated thermal scope on your rifle and a hand-held thermal monocular or binocular. These handhelds, called thermal viewers, enable you to scan the landscape and detect targets. Many have built-in rangefinders that allow you to measure the distance to the animal, and they often have enough resolution to determine the difference between a domestic dog and a coyote.
Once you’ve determined that the target is one you want to shoot, you can deploy your thermal riflescope to the task of placing your bullet. I find that employing a buddy system is the best way to maximize your success with thermals. One of you has the viewer, the other is on the rifle.
HOW TO PICK A THERMAL The thermal category is blowing up, with new devices introduced every year. But which is best for you, what features should you look for and which are worth the price?
First, you should determine if you need a dedicated thermal riflescope or if you’d prefer a clip-on thermal that turns your daylight riflescope into a thermal. There are advantages and disadvantages to each. Dedicated thermal scopes tend to be more robust and have more features like interchangeable reticles and electronic zeroing, as well as longer battery life. But clip-ons are handy because once the sun comes up you can simply remove the thermal and use your riflescope as you always have.
When choosing between a handheld monocular and a thermal binocular, know that they generally work the same; there is no such thing as true binocular vision with these. Instead, binoculars are generally monoculars with two barrels. But you’ll want to decide if you want a built-in rangefinder, image stabilization and Wi-Fi transmission to your phone, all features found on high-end viewers.
In either platform, scopes or viewers, pay careful attention to the manufacturer’s stated resolution. Thermal devices have a rating for the sensitivity of their sensors and for the fineness of their digital display. The higher the number (measured in pixels) for either or both, the better the image you’ll receive. But, just like in traditional optics, you’ll pay for higher resolution. Generally, thermals with 640x480-pixel sensors have pretty good images and detection ranges, but make sure that the display resolution is at least as large as the sensor resolution. If you can get a thermal display resolution of 1024x768 pixels, you will have a high-performing unit.
Thermal optics come in many forms, from standalone scopes and clip-on devices that attach to typical scopes, to handheld binos and monoculars. (Photo by Greg Duncan) The problem with budget-basement thermals is that they generally have very poor resolution. They can detect heat signatures of large animals at close range, but they tend to be indistinct and can cause problems if you’re trying to decide whether that incoming animal is a coyote or a fawn.
Just like with daylight optics, the larger the objective lens on a thermal, the better the image it delivers, generally speaking. Large objective lenses on thermal optics don’t collect light, but the lens material (an element called germanium) converts minute differentials in temperature to digital images. The more germanium, the more sensitive the thermal device. Realize, though, that because germanium is an expensive material, you’ll pay more for thermals with larger objective lenses.
Modern thermal optics have created predator hunting opportunities that didn’t exist even a decade ago. (Shutterstock photo) Most thermals have digital zoom magnification, but in a digital device, the magnification really just makes the image larger and more pixelated. So, approach zoom ranges with a bit of skepticism; the best range in magnification for hunting is from about 2X up to about 6X. Above that, the image gets too blurry to be useful. Also note that clip-on thermals, because they use the magnification of the host scope, are usually non-magnified.
Most thermal devices have the ability to record video, still images or both. Image capture is a great way to share your hunt or to save videos to your phone for later review. Look for devices that have Wi-Fi transmitters and connectivity to a mobile app for ease of image sharing. Some devices have on-board image storage that require either a cord or memory cards to transfer images.
Bottom line: thermals are almost like magic, revealing images that are hidden to most of us in the dark. But, in order to maximize your success as a night-hunter, you need to understand what these devices can and can’t do and be prepared to pay for the best unit you can afford. In that way, thermals are just like any other piece of a hunter’s kit.
BUDGET THERMAL Cost-conscious options for those just getting their feet wet in thermal hunting The average price of a decent thermal, one that has adequate resolution, wireless image capture and transfer, and compatibility with a mobile app, is about $3,500. That’s a huge chunk of money for a device that has limited utility and that you might only use a few times a year. But savvy shoppers can find good devices for about half that amount that will at least get them in the game and help them determine whether thermal hunting is worth a deeper investment.
Sightmark Wraith Mini Thermal Photo courtesy of Sightmark Retailing for about $1,700, this dedicated thermal scope will get you in the predator and hog game with all the features you need for a pretty accessible price. The Wraith has only a 384x288-pixel sensor resolution, but the 1024x768-pixel display maximizes the image. The scope has five color palettes, a 1,400-yard detection range, the choice of 10 different reticles, 1- to 8-power digital zoom and a built-in mount that easily fits most receiver rails. Unfortunately, it doesn’t connect to the excellent StreamVision2 app that runs most Pulsar thermals (Sightmark is a cousin company of Pulsar). The Wraith records both video and stills, but you’ll need to manually transfer them from the unit.
Athlon Cronus ATS 35ML-400 Photo courtesy of Athlon Optics This hand-held monocular has the basics: decent resolution, a built-in 1,100-yard laser rangefinder and Wi-Fi connectivity to the Athlon Thermal app, where users can record and share videos and stills. Its 400x300-pixel sensor resolution is on the low end, but the unit is simple to use and its buttons are both ergonomic and intuitive. The retail price is $2,375, but shrewd shoppers should be able to find it on sale for around $1,750.
ATN THOR LTV 256 Photo courtesy of ATN Corp This is about as basic, and as inexpensive, as you’re going to find in a name-brand thermal scope. The ATN THOR family has a lot of different variations, but the 1.5- to 4.5-power scope, with a tiny 12 mm objective lens, costs about $879. The entry-level scope has a 256x192-pixel sensor that’s boosted by a 1280x720-pixel display. It has just two color modes (white-hot and black-hot), a limited recognition range of just 129 yards and it records video and photos to an on-board microSD card. You’ll need your own 30 mm standard rings to mount this, but the THOR looks, and behaves, like a traditional riflescope.
Xinfrared T2 Pro Photo courtesy of Xinfrared This tiny marvel is only a little larger than a sugar cube and costs only about $400, but it’s a fairly decent thermal with a number of color palettes and both video and still-image capture capability. It can do so much because it doesn’t have a screen; it uses your mobile phone’s display instead. The unit plugs into your phone’s charging port and is then controlled by a mobile app. Billed as “the world’s smallest thermal” it has limited use for hunting but will allow users to see what’s out there in the night.
This article was featured in the February 2025 issue of Game & Fish magazine. Click to subscribe .
