The Calonox 2 View runs a 640×480 core at 12 µm behind a 42 mm lens; the DTI 6/40 runs 640×480 at 12 µm behind 40 mm. On the Johnson yardstick they detect a person at 875 m and 833 m and recognize one at 219 m and 208 m; the boxes say 2,210 m and 2,000 m. The Calonox 2 View is lighter by 3.9 oz. Approximate prices are ~$4,899 and ~$4,800.
Estimated range, standing human, clear air
IdentifyRecognizeDetectBox claim
Leica Calonox 2 View640×480 · 12 µm · 42 mm
135 m identify219 m recognize875 m detectbox says 2,210 m (1.7 m x 0.5 m subject at 2 px (Leica 'recognition' 770 m at 6 px))
Zeiss DTI 6/40640×480 · 12 µm · 40 mm
128 m identify208 m recognize833 m detectbox says 2,000 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.