186° IR Corrected Fisheye M12 Lens for 1/1.8" Day/Night Cameras

CIL239 is a 1.8mm F/2.0 IR corrected fisheye M12 lens with a 186-degree field of view at a 5.2mm image circle. It is built for day/night imaging systems. IR correction keeps focal shift under 8 microns from 550nm to 850nm, so the lens stays sharp whether the 650nm cut filter is in or out.

That stability matters in any system that switches illumination modes without a mechanical focus adjustment. If the camera has to move from visible light to NIR and keep the same calibration, this lens addresses that directly.

Format coverage tops out at 12MP on 1/1.8" sensors such as the Sony IMX334. At 8MP and 1.85µm pixel pitch, the lens gives solid resolution for embedded vision. The 5.2mm image circle matches the 1/1.8" format closely, so you are not carrying unused coverage. Distortion is -13% F-θ, which is normal barrel distortion for this FoV class, so plan on software correction if the application measures geometry near the edge.

One mechanical variant is available. M12A uses BBAR anti-reflection coating on the first lens surface with an all-metal cap and barrel, but it has no ingress protection. Outdoor and high-humidity installs need an enclosure. Order CIL239-F2.0-M12A650 with the 650nm IRC filter or CIL239-F2.0-M12ANIR without the filter.

Allied Vision Alvium, FLIR Blackfly S, iDS uEye LE Rev1.1 and Rev1.2, The Imaging Source M12, and Basler Dart S-Mount boards are mechanically confirmed with a standard 9mm-13mm M12 holder. The Commonlands CLA018 holder is the cleanest fit. STP files and mechanical drawings are available on the product page, orders placed before 12 PM PST ship same day from San Diego, and volume pricing starts at 50 units.