FL13.5mm F#1.0 Long Wave Infrared Thermal Sight Lens for 640x512-24um Detector

The 13.5mm F1.0 LWIR Thermal Sight Lens is a wide-angle, high-speed infrared optic designed for 640×512–24μm detectors, delivering an expansive 71.7°×55.3° field of view for superior situational awareness and close-range target detection. With an ultra-fast F/1.0 aperture and >85% average transmission across the 8–12μm band, it ensures bright, clear thermal imagery even in challenging low-light or low-contrast conditions. The fixed-focus design operates from 1.5m to infinity, making it ideal for helmet-mounted systems, vehicle peripheral vision, and handheld surveillance applications where rapid scene acquisition is critical.

Weighing just 108g with compact φ47mm×44mm dimensions, this lens features an M45×0.75-6g thread mount and is engineered for rugged field performance across –40°C to +80°C. The integrated DLC (diamond-like carbon) coating provides exceptional scratch resistance and surface durability, ensuring reliable operation in harsh environments. With precise back focal distances (35.19mm BFD, 27.69mm BWD, 28.26mm BFL), this lens offers straightforward integration into a wide range of LWIR thermal imaging systems.