FシータM12レンズ｜180°@7.5mm、5MP、2/3インチまで対応（ISX031など

CIL926 is an ultra-wide M12 lens with a 2.5mm effective focal length, F/2.4 aperture, and 172° field of view. It is specified for sensors up to 1/2.5", uses a 7.4mm image circle, supports 5MP with 2μm pixels, and weighs 12g. That is a lot of coverage without stepping into a circular fisheye format.

The main optical feature is the F-Theta distortion profile. Commonlands lists the distortion at about -1.4% F-θ, which is low for this field angle and keeps angular mapping more uniform across the image. That matters when you care about wide scene measurement or stable geometry from center to edge instead of just getting a dramatic picture.

The mechanics use an all-glass, aluminum construction rather than a mixed-material stack. That usually holds focus better across temperature changes and makes the lens easier to trust in outdoor hardware. The listed version is IP67, so it fits exposed cameras much better than a non-sealed indoor lens.

If you need more than 170° of coverage without moving to a circular fisheye, the CIL926 is one of the cleaner options in this size class. The 2.5mm EFL, 7.4mm image circle, and low F-Theta distortion point it at wide embedded vision systems that still need usable geometry.