When it comes to thermal optics, there are dozens of talking points; however, purposes, image-enhancing features and price points always rank within the most popular three — top five for ridiculously rocket-sciencey folks. Of course, this makes sense, since virtually every cool-factor related to thermal optics is rich in science-based advancing technologies, including their rare, cool and costly germanium objective lenses (located at the front of every device).
Purposes vary nearly as widely as the people who use them. Without question, thermal is perfectly suited to unlock the mysteries of the night; however, this is where some folks get confused. Thermal is definitely not night vision. While they both lift the veil of darkness, they are completely different technologies; in fact, thermal is a true 24-hour optic. It doesn’t care what time of day it is. It only cares about varying temperatures in a field of view. In technology-speak, this is rated as NETD (Noise Equivalency Temperature Differential — the lower the number, the smaller the detected temperature differences, resulting in a more detailed image.
All said, yes, the overarching use of thermal imaging is for nighttime viewing. Outdoor enthusiasts use thermal for hunting and nighttime wildlife surveillance. Farmers and ranchers use thermal to detect predators and wildlife and to observe or count their livestock. Border patrol agents and border-living ranchers and farmers use thermal to detect illegal immigrants entering the U.S. or traveling through ranches (around homes and outbuildings). Boaters use thermal to detect boats running without lights, hazards in waterways, overboard people and activity on various shores and banks. Law enforcement officers use thermal for surveillance and fugitive recovery. First responders use thermal for search and rescue operations. Fire departments use thermal to detect hot spots once fires are extinguished. Contractors use thermals to troubleshoot and detect things like electrical shorts in walls. My wife uses it as a stud sensor to make me hang more things in our home. (Update: I now keep it in my gun safe because she continually forgets the combination.)
Image-enhancing features (or lack of) are pretty standard across the consumer thermal-imaging industry. Users should focus on sensor resolution, pixel pitch, NETD rating and detection ranges. Top-tier sensor resolution is 1280x1024 or 1024x768, with high-performance mid-range resolution at 640x480. On the low end of premium performance thermal is 384x288 and even 320x240. The higher the number, the better the resolution; however, image quality, even from lower resolution sensors, can be incredibly crisp with the right combinations of pixel pitch and NETD. The most popular pixel pitch ratings are 12 or 17 microns — the lower the number, the better the pixel-pitch rating. Pixel pitch is simply the measurement from the center of one pixel to the center of the pixel next to it. Finally, NETD should be sub-40mK. This is the premium thermal standard. The lower the number the better. Some thermals boast NETD as low as sub-18 (the industry call-out is <18mK NETD).
Among current thermal users, enhanced imaging and feature sets are the hottest topics. For new users and those in discovery mode, price point is the primary focus. While thermal cost as much as $15,000 to $30,000 just 10 to 15 years ago, just like CD players and microwave ovens, costs have plummeted while technology continues to improve. Even so, and while there has never been a better time to buy, thermal imaging is still considered expensive.
For shooters and hunters looking for a dedicated thermal riflescope, prices start at about $1,700. A good example is the Sightmark Wraith 2-16x35 Thermal Riflescope. Of course, prices can easily still top $10,000. The goods news here is that for $1,700, the Sightmark Wraith Mini Thermal still delivers a superb performance-thermal experience packed with more capabilities and features than most shooters and hunters need.
The Sightmark Wraith 2-16x35 Mini Thermal Riflescope boasts 2x optical magnification and 1-8x zoom, 35mm enhanced germanium-glass objective lens, Lynred 384x288 microbolometer sensor, 17-micron pixel pitch, <40mK NETD sensitivity, 1024x768 OLED display, five-color display palette and a 1,400-yard adult-size heat-signature detection range. At roughly the size of an ACOG sight and weighing less than 20 ounces, the Wraith Mini Thermal is also exceptionally compact and lightweight, yet built tough — recoil rated up to .308 Winchester and IPX6 waterproof rated. The Wraith Mini Thermal also features 10 reticle styles in nine color options for a customized field of view, five firearm profiles, built-in video to a micro-SD card (sold separately), flip-up lens protectors, rubbery eyecup and a Picatinny-rail-compatible mount. The Wraith Mini is powered for up to 4.4 hours with two CR123A batteries and is compatible with the Picatinny-mountable Sightmark Mini QD Battery Pack for more than 8 hours of operation. The Wraith also comes with two CR123 batteries, USB cable and a three-year warranty. Learn more at www.Sightmark.com.
