• Open‑country hunters who need to detect and identify heat signatures past 1,000 yards
• Search‑and‑rescue, border security or marine users requiring maximum range in a handheld unit
• Professional users who prioritize resolution and reach over compactness and weight

• Dense woods or confined environments where a wide field of view is more important
• Long hikes where the added weight (≈1 lb) becomes noticeable
• Budget‑conscious buyers or those who don’t need detection past about 1,500 yards

The 50‑640 represents the top tier of the ReachIR family. Its 50 mm objective and 640 sensor deliver the longest detection range—AGM lists detection up to ~2.6 km on a 6‑ft target—but the trade‑off is a narrower field of view and greater weight. The 35‑640 offers a wider view and lower weight with slightly less range, while the 25‑384 is lightest and most affordable but has lower resolution and roughly half the detection distance.

Compared to the 35‑640, the 50‑640 extends detection from ~1.8 km to ~2.6 km and increases optical magnification from 2× to 3×. The downside is a narrower field of view (8.7° vs 12.5°) and more weight.

Field reports show the 50‑640 excels for spotting coyotes, deer and people far across open pastures or along lake shores. Positive identification is possible out to ~700–800 yards thanks to the 3× base magnification and high‑resolution sensor. The integrated rangefinder is accurate to a yard up to ~1,000 m and is helpful for adjusting ballistic drop. Digital zoom up to 8× is available, though clarity diminishes at high zoom.

The battery provides about 4 hours of runtime, so a spare 18650 or external power bank is advisable. Because the lens is larger, the unit is heavier and somewhat front‑heavy, but it remains comfortable for handheld use with a wrist strap.

• 640×512 12 µm VOx sensor with <20 mK sensitivity
• 50 mm f/1.0 germanium lens; 3× optical magnification with 1×/2×/4×/8× digital zoom
• Detection range up to 2.6 km; integrated 1,000‑m laser rangefinder
• 50 Hz refresh rate and 1024×768 OLED display
• 64 GB internal memory for video and audio recording
• Replaceable 18650 battery provides about 4 hours runtime
• Wi‑Fi hotspot for live streaming and file transfer
• IP67‑rated magnesium alloy housing with 5‑year warranty

At the pinnacle of AGM's handheld rangefinder line is the ReachIR LRF 50‑640, engineered to deliver maximum range and resolution. Its 50 mm f/1.0 germanium lens collects more thermal energy, resulting in a 3× base magnification and longer detection distances than smaller models. The 640×512 thermal core and advanced image processing provide crisp imagery, while a fast 50 Hz refresh keeps moving targets smooth.

Despite its long‑range capability, the unit is still handheld and features an integrated 1,000‑m laser rangefinder. A generous 64 GB of onboard storage records hours of video with audio. Wi‑Fi connectivity allows remote viewing and file transfer via the AGM app.

Power is supplied by a removable 18650 battery for roughly 4 hours, and the IP67‑rated magnesium chassis protects the optic from dust, rain and shock. For open‑country hunters, search‑and‑rescue teams and professional users who demand the longest possible detection in a handheld, the ReachIR 50‑640 is hard to beat.

• Detector: 12 µm VOx uncooled FPA, 640×512 resolution, NETD <20 mK
• Lens system: 50 mm f/1.0; field of view 8.7° × 7.0°
• Optical magnification: 3× (digital zoom 1–8×)
• Detection range (6‑ft target): ≈2,600 m; laser rangefinder range: 1,000 m
• Display: 0.39‑inch OLED, 1024×768, 50 Hz refresh
• Memory: 64 GB internal storage for photos and video with audio
• Power: one removable 18650 battery; ≈4 h runtime; USB‑C external power
• Dimensions/weight: ~7.4 × 3.4 × 2 in; ~16 oz
• Environmental: IP67 waterproof; operating temp –22 °F to +131 °F
• Warranty: 5 years transferable on the optic and sensor