When you need to find warm-bodied animals in the dark and then confirm exactly what you are looking at, the Ventus 635L handles both jobs in one binocular. Its 640×512 thermal channel, with NETD below 15mK, picks up heat signatures out to 1800 m. A separate 3536×3536 day/night CMOS channel with a switchable 850nm/940nm IR illuminator lets you see detail to 400 m at night on the 850nm setting. You move from infrared to daylight without refocusing, or view both channels together in Picture-in-Picture.

The thermal channel magnifies from 2.6x to 10.4x and the day/night channel from 4x to 24x, shown on a 1600×1200 AMOLED display. A built-in Class 1 laser rangefinder reads to 1000 m within ±1 m, and a digital magnetic compass gives you a bearing. Photos and video, with audio, are stored on 64GB of internal memory.

The two focus wheels sit together so you can work both with one hand, the rubber-coated frame is IP67 rated, and the eyepieces adjust from 60 mm to 72 mm. A proximity sensor turns the screen off when you lower the binocular to save power.

Plan around power: two replaceable 18650 cells give about 6 hours, so carry spares for a long night. The binocular weighs 825 g and is rated to operate from -20°C to 50°C.