Tested in the Field: ThermTec Hunt650L and Hunt635 PRO
- Hans ARC
- 5 days ago
- 5 min read
Modern thermal technology is no longer a gadget—it has become an essential tool for responsible hunting. Clip-on thermal devices provide control, reliable target identification, and well-founded decision-making. Two units currently in high demand were tested extensively in real hunting conditions by experienced hunters and the Schuss & Stille team over several weeks: the ThermTec Hunt 650L with integrated laser rangefinder and the ThermTec Hunt635 PRO.
Nighttime activity in the field has increased significantly. High wild boar populations, rising damage to crops and forests, and the expanding presence of species such as beaver and wolf present hunters with new challenges. Anyone responsible for wildlife management, cultivated landscapes, and public safety increasingly reaches the point where hunting after dark becomes necessary—quietly, safely, and ethically.
A hunting tool should never dominate the experience. It should blend in, operate silently, and function reliably when it matters most. Especially with clip-on systems, true quality reveals itself not on a spec sheet, but in the silent moment before the shot. Both ThermTec-devices follow this philosophy. They are compact, robust, clearly laid out, and deliberately free of unnecessary gimmicks. Operation is intuitive, startup time is fast—a real advantage—and both units operate silently, a critical detail during long sits.
How Clip-On Thermal Devices Work – Simply Explained
A clip-on thermal device essentially acts as a small screen placed in front of your riflescope. The thermal unit mounts to the front of the daytime optic and projects its image onto an internal display. When looking through the scope, the hunter is not viewing the terrain directly, but this small screen, which shows the image generated by the thermal sensor.
The riflescope itself remains unchanged: magnification, reticle, and zero stay exactly the same. The clip-on only provides the image—the shot is still taken using the familiar reticle of the daytime optic. Because thermal imaging works independently of ambient light, game animals remain clearly visible even in complete darkness or poor visibility. When properly mounted and used, a clip-on does not alter point of impact or shooting feel—it simply expands the hunter’s perception.
ThermTec Hunt650L – Precision with Distance Control
The Hunt650L is a classic clip-on designed for precise rifle use. At its core is a 640 × 512 VOx sensor with a 12 μm pixel pitch. Combined with fast optics, this results in a calm, high-contrast image that performs exceptionally well even in high humidity, fog, or minimal temperature differences. Thermal sensitivity (NETD) is rated below 20 mK, delivering impressive fine detail in real-world use.
Game animals stand out clearly from the background without artificial over-enhancement. Legs, head position, and body posture remain easy to identify—an essential advantage for confident target identification. A defining feature of the Hunt650L is its integrated laser rangefinder, capable of accurately measuring distances up to 600 meters. Especially at night, in open fields or along forest edges, this adds a significant safety margin. Distances no longer need to be estimated—they are known. That knowledge directly influences decision-making and responsibility.
In testing, mounting the device in front of the daytime optic was straightforward, and point of impact remained stable even after repeated removal and reattachment. In practical hunting terms, this reliability is non-negotiable. The ThermTec Hunt650L currently retails between €2,999 and €3,099, depending on dealer and accessories.
ThermTec Hunt635 PRO
The Hunt635 PRO is also a clip-on device, featuring the same 640-resolution sensor with 12 μm pixel pitch. Its image presentation is slightly wider, and the unit itself is more compact and exceptionally well balanced. Movement is easy to track and animal behavior is clearly readable—particularly beneficial when hunting wild boar or predators. Image detail remains sufficient even at longer distances to determine whether an animal is moving, standing, or alert.
The ThermTec Hunt635 PRO is currently priced between €2,299 and €2,449, positioning it as a highly attractive option within its performance class.
Power Supply – Designed for the Field
One practical detail that quickly proves decisive in real hunting scenarios is the battery system. Both ThermTec clip-on devices use swappable batteries that slide onto the unit from below.
Battery changes are silent, even in complete darkness and while wearing gloves—no screws, no fumbling, and no need to remove the device from the rifle. During long nights or cold temperatures, this is a major advantage. Battery life averages around six hours depending on use, and can be extended indefinitely through quick swaps.
Field Experience
In addition to the Schuss & Stille team, the Hunt650L was extensively tested by Johannes Leitner, longtime head of the Feistritz an der Gail hunting association. Leitner used the device not only on the rifle, but intentionally also for observation. “The image quality is so good that you really don’t need a separate handheld unit,” says Leitner.
During one evening sit, Leitner observed a rutting red stag standing at the forest edge in the last moments of legal shooting light. The animal was clearly visible, the image calm and stable, and its behavior easy to interpret. While using a clip-on as a handheld device naturally involves some compromise, Leitner describes the Hunt650L as an outstanding tool for everyday hunting—especially given its price point.
Local game warden Peter Hebein highlights another often-overlooked detail: operation. He is particularly impressed by the on/off control of the Hunt650L. The device is immediately ready for use, and the small lever on the left side can be located easily even in total darkness. During a stand, when seconds matter, such details inspire confidence.
Confirmation Shot – Not Technically Required, Ethically Essential
After mounting the clip-on devices, a confirmation shot was fired in every case. The result was clear: every shot landed exactly on point, with no noticeable deviation from the known zero. From a purely technical standpoint, the confirmation shot would not have been necessary—the mounting was repeatable and the systems proved absolutely stable. Ethically, however, a confirmation shot remains essential. It builds trust, confirms the equipment, and is an integral part of responsible, ethical hunting practice.
Clear Evaluation from a Hunter’s Perspective
After several weeks of practical field use, one conclusion stands out clearly: in our opinion, ThermTec’s clip-on devices currently rank among the best available in their price class. Image quality, ease of use, build quality, and reliability form a highly convincing package relative to cost.
Hunters seeking a powerful, field-proven clip-on that delivers strong technical performance while remaining ethically and practically sound will find two exceptionally well-balanced options in the Hunt650L and the Hunt635 PRO, both offering outstanding value for money.
Transparency Notice
The devices used in this test were provided by Thermfox, the general importer of ThermTec products in Austria and Switzerland, as well as Alpe Adria Jagd Villach. All evaluations were conducted independently, under real hunting conditions, and without commercial influence.
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