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

The CIL239 is a 1.8mm F/2.0 IR corrected fisheye M12 lens with a 186° field of view at 5.2mm image circle. It's built specifically for day/night imaging systems — the IR correction holds focal shift under 8 microns from 550nm to 850nm, so the lens stays sharp whether the 650nm cut filter is in or out. That matters in any system that switches illumination modes without a mechanical focus adjustment.

Format compatibility tops out at 12MP on 1/1.8" sensors like the Sony IMX334. At 8MP and 1.85µm pixel pitch, resolution is solid for embedded vision tasks. The 5.2mm image circle matches the 1/1.8" format closely — you're not carrying coverage you don't use. Distortion is -13% F-θ, which is barrel distortion typical of this FoV class. Objects toward the field edges will curve; factor that into any measurement or detection pipeline.

One mechanical variant is available: M12A, using BBAR anti-reflection coating on the first lens surface with an all-metal cap and barrel. There's no ingress protection on this variant. Outdoor use or high-humidity deployments need an enclosure. The lens ships with or without a 650nm IRC filter pre-installed — order CIL239-F2.0-M12A650 for the filter, or CIL239-F2.0-M12ANIR for the bare lens.

Camera compatibility is broad for standard 9mm-13mm M12 holders. Allied Vision Alvium, FLIR Blackfly S, iDS uEye LE (both Rev1.1 and Rev1.2), The Imaging Source M12, and Basler Dart S-Mount boards are all mechanically confirmed. Use the Commonlands CLA018 lens holder for an optimized fit.

STP files and mechanical drawings are available on the product page. Ships same day from San Diego before 12 PM PST. Volume pricing starts at 50 units — contact us for a formal quote.