Pulsar Krypton 2 FXG50 vs Pulsar Thermion 2 LRF XP50 Pro
The Krypton 2 FXG50 runs a 640×480 core at 12 µm behind a 50 mm lens; the Thermion 2 LRF XP50 Pro runs 640×480 at 17 µm behind 50 mm. On the Johnson yardstick they detect a person at 1,042 m and 735 m and recognize one at 260 m and 184 m; the boxes say 2,300 m and 1,800 m. The Krypton 2 FXG50 is lighter by 16.5 oz. Approximate prices are ~$5,000 and ~$4,000.
Estimated range, standing human, clear air
IdentifyRecognizeDetectBox claim
Pulsar Krypton 2 FXG50640×480 · 12 µm · 50 mm
160 m identify260 m recognize1,042 m detectbox says 2,300 m (1.8 m object)
113 m identify184 m recognize735 m detectbox says 1,800 m (unspecified)
501002005001k2k5k m
Estimated from pixel pitch and lens focal length using the Johnson criteria (2, 8 and 13 pixels across a 0.5 m human critical dimension), clear air, 50 % probability. A model of the optics, not a measurement — real range depends on temperature contrast, humidity and the animal.