200° M12 Miniature Fisheye Lens for up to 1/1.8"" such as IMX728 and AR0823

190°@9.1mm Fisheye M12 Lens

The CIL231 is a 3.1mm miniature fisheye lens which provides a 190° Field of View at 9.1mm Image Circle and 180° diagonal on 1/1.8" type sensors. The aperture of F/1.9 results in amazing low light performance with stunning 4K+ performance. The CIL231 is IP67 sealed.
$99.00

58pcs CIL231-F1.9-M12A650 (F/1.9 / M12A / With 650nm IRC Filter) in stock in the US

59pcs CIL231-F1.9-M12ANIR (F/1.9 / M12A / Without Filter) in stock in the US

In stock — orders before 12 PM PST ship same day

Lens Features

Low F/#

All-glass all-metal design, with F/1.9 for incredible low light performance.

IP67

IP67 rated for dust and water resistance.

Optical and Mechanical Specification Table

Lens Parameter Performance Detail
Part NumberCIL231
EFL3.1
F# 1.9
Resolution12MP+, 1.55μm
Field of View190° @ 9.1mm image circle — Calculate FoV for your sensor
Image Circle9.0mm
Distortion-10% FΘ @9.1mm
See [mechanical drawing](https://docsend.com/view/s/9srqiufx3zuw89hj) for Optical, FΘ, and full TV distortion.
Weight12g
IR Cut-Off FilterP/N With: CIL231-F1.9-M12A650
P/N Without: CIL231-F1.9-M12ANIR
ConstructionAll Glass, Aluminum

Mechanical Variants

Variant Description
M12A IP67, BBAR on Lens 1 Surface 1, Metal Cap+Barrel

Mechanical Layout

Camera Mechanical Compatibility Table*

*Mechanical compatibility only, assuming the standard M12x0.5 lens mount provided by the camera manufacturer. Please check optical compatibility separately.

Same Day Ship by 12 PM PST
US-Based Optical Engineering Support
25,000+ Stock in California
100% MTF Tested

Frequently asked questions

What sensors work with the CIL231 3mm fisheye M12 lens?

The CIL231 covers 1/1.8 inch sensors including the Sony IMX728 and ON Semiconductor AR0823. It resolves 12MP+ at 1.55μm pixel pitch across a 9.0mm image circle.

What is the field of view of the CIL231 fisheye lens?

The CIL231 gives 190° field of view at the 9.1mm image circle. Use field of view calculator if you want the exact coverage on your sensor format.

Is the CIL231 IP67 waterproof?

Yes, the M12A variant of the CIL231 is IP67 sealed with a metal cap and barrel. It is rated for dust ingress and water immersion.

What is the distortion type on the CIL231 fisheye lens?

The CIL231 uses -10% F-theta distortion. That projection spreads angular resolution more evenly across the frame than an equidistant fisheye, which helps panoramic stitching and surround-view work.

Which M12 lens holders are compatible with the CIL231?

The Commonlands CLA019-LCP holder (8-13mm standoff) is one compatible mounting option. The lens also fits standard M12x0.5 mounts from e-con Systems, Allied Vision, FLIR, iDS, The Imaging Source, and Basler.

Does the CIL231 3mm M12 fisheye lens ship same day from the US?

Yes, in-stock CIL231 lenses ship same day from San Diego, California for orders placed before 12 PM PST. Over 60 units of each CIL231 variant are currently in stock.

The CIL231 is a 3.1mm M12 fisheye lens with 190° field of view on 1/1.8 inch sensors such as the IMX728 and AR0823. It uses a fixed F/1.9 aperture, all-glass optics in an aluminum barrel, IP67 sealing, and a 12g package, so it fits outdoor or washdown systems that still need high pixel density.

The lens uses -10% F-theta distortion. That projection spreads angular resolution more evenly across the frame than a standard equidistant fisheye, which helps when stitched panoramic views or surround-view systems still need useful edge detail instead of wasting pixels in the center. The lens resolves 12MP+ at 1.55μm pixel pitch across the full 190° field. You can check sensor coverage the field of view calculator

All-glass elements and BBAR coating on the first surface help control flare. The sealed M12A metal barrel handles dust, rain, and washdown environments without needing a second enclosure around the lens. Order CIL231-F1.9-M12A650 with the 650nm IR cut filter for daylight imaging, or CIL231-F1.9-M12ANIR for NIR-sensitive applications.

The lens mounts to Commonlands CLA019-LCP holders with 8-13mm standoff. It is mechanically compatible with e-con Systems, Allied Vision Alvium, FLIR Blackfly S, iDS uEye XLS, The Imaging Source, and Basler Dart S-mount board cameras.

Commonlands ships this lens same day from San Diego for orders placed before 12 PM PST. Contact our optical engineers if you need volume pricing or STP files for CAD integration.

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About Commonlands

Commonlands LLC designs and manufactures precision M12, C-mount, and M8 lenses for machine vision, robotics, and embedded camera systems. Based in San Diego, California, we stock inventory for same-day shipping and provide direct access to US-based optical engineers. Whether you need a single prototype lens or production volumes of 25,000+, our team supports the full lifecycle from optical design consultation through volume fulfillment.

Need help selecting the right lens for your camera module?

Contact our US-based Optical Engineers.