Leica Calonox 2 Sight LRF vs Pulsar Krypton 2 FXG50
The Calonox 2 Sight LRF runs a 640×480 core at 12 µm behind a 42 mm lens; the Krypton 2 FXG50 runs 640×480 at 12 µm behind 50 mm. On the Johnson yardstick they detect a person at 875 m and 1,042 m and recognize one at 219 m and 260 m; the boxes say 2,210 m and 2,300 m. The Krypton 2 FXG50 is lighter by 2.6 oz. Approximate prices are ~$5,899 and ~$5,000.
Estimated range, standing human, clear air
IdentifyRecognizeDetectBox claim
Leica Calonox 2 Sight LRF640×480 · 12 µm · 42 mm
135 m identify219 m recognize875 m detectbox says 2,210 m (1.7 m x 0.5 m subject, Leica 'acquisition' at 2 px (Leica 'detection' 770 m at 6 px))
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)
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.