JSD2157 168° M12 Lens – 2.35mm IP 67 Ultra Wide Angle
JSD2157: A 168°; DFOV M12 Lens Built to Make Wide-Angle Design Decisions Easier
A 2.35mm M12 lens that holds a 168°; diagonal field of view across a 6.7mm image circle, built from 6 glass elements in a sealed aluminum barrel.
Key takeaway: The JSD2157 is a 2.35mm M12 lens that delivers a 168°; diagonal field of view across a 6.7mm image circle, which covers the 1/2.8" sensor class at 2MP and beyond. Its 6-element all-glass construction, aluminum barrel and IP 67 sealing are what make the part buildable in module volume and viable outdoors.
Why 168°; on a Small Format Is a Design Constraint, Not a Spec Sheet Line
Field of view is the easiest number to print on a datasheet and the most difficult one to deliver. A requirement in the region of 170°; diagonal sounds generous until it meets a small image format, and then three engineering budgets start competing for the same millimetres: edge illumination, edge sharpness, and geometric accuracy across the frame.
The corner is the first constraint to appear. Light arriving at a steep angle at the edge of a wide field travels a longer path than light entering on axis, so brightness falls away from the centre, and the falloff deepens as the design is pushed wider. Resolution behaves the same way. Those steep angles make a tight spot size progressively harder to hold toward the corner of the sensor, which is where a 2MP module records the number plate, the pedestrian, or the edge of the room.
Geometric accuracy is the third constraint, and it is the one that shows up in the bill of materials rather than in the datasheet. A field this wide cannot be projected onto a flat sensor as a geometrically faithful rectangle. The correction can be bought once at design time in the optics, or paid per unit in the image signal processing chain, and the choice sets both the envelope and the processing budget of the module.
Those three constraints are one decision rather than three. A 168°; DFOV wide angle lens is useful only when the figure is delivered together with an image circle that covers the sensor, a barrel that fits the housing, and a level of geometric fidelity the project is prepared to work with. The JSD2157 is a standard part aimed at that combination.
What 168°; Actually Means on a 1/2.8" Sensor
Three numbers carry the part in application terms, and each one answers a different question a design team is already asking.
The 6.7mm image circle. A 1/2.8" sensor needs roughly a 6.4mm circle, so the extra 0.3mm is clearance rather than headroom. That is where corner illumination and mounting tolerance are decided, and it is the figure to re-check before the geometry is frozen, because a larger format is a different part, not a different setting.
The 168°; diagonal field of view. Ultra wide angle is a range, not a label. On a 16:9 sensor the 168°; diagonal resolves to about 148°; horizontally and 80°; vertically, so the frame is a wide horizontal field with modest vertical reach. That balance suits blind-spot coverage, door entry and interior overview, where the subject sits closer to the camera than a normal-field module assumes.
The 2.35mm focal length at F2.0. A short focal length is what buys the wide field in a compact barrel, while the aperture is what keeps exposure workable indoors, in a corridor, or in the shade of a vehicle body. F2.0 also leaves the depth of field shallow enough that focus has to be set and locked deliberately rather than left to chance.
Where a project needs a narrower field, the same 2MP class of module can be served by a lens built for 1/2.8" sensors in a longer focal length. The reason to start from the sensor rather than the focal length is that the image circle decides which of those options are physically available.
JSD2157 Specifications and What Each Number Changes
The table below is the working specification for the JSD2157, paired with the consequence of each figure so the numbers can be carried straight into a mechanical model and a purchasing decision.
| Parameter | Specification | Design impact |
|---|---|---|
| Part number | JSD2157 | — |
| Focal length | 2.35mm | Produces the ultra wide field without a large front element |
| Aperture | F2.0 | Holds exposure in low-light coverage scenes; demands deliberate focus lock |
| Field of view | 168°; DFOV / 148°; HFOV / 80°; VFOV | Sets coverage in all three axes; the diagonal alone is not enough to model |
| Image circle | 6.7mm | Covers a 1/2.8" sensor with a small margin at the corners |
| Resolution | 5MP | Rated above the 2MP sensor class, so edge sharpness survives correction |
| Optical construction | 6 elements, all glass (6G) | All-glass construction keeps geometry and focus stable over temperature |
| Barrel | Aluminum exterior | Supports the −20°;C to +85°;C operating window and long-term mounting stability |
| Mount | M12 S mount | Uses the standard holder platform shared with other JSD wide-angle parts |
| Thread | M12 × P0.5 | Determines the holder bore and the focus-locking arrangement |
| Barrel outer diameter | φ17mm | Sets the minimum bore for the front housing opening |
| TTL | 22mm | The front-to-sensor length the mechanical engineer needs first |
| Sealing | IP 67 | Points outdoor, door entry and vehicle-mounted modules at this part |
| Spectral configuration | 650nm and 850nm filter options | Confirmed per project rather than inferred from the part number |
Two notes on reading the table.
The field of view triplet is stated for the 1/2.8" class image circle; a different sensor format moves all three values, so they are re-checked against the actual sensor before they enter a mechanical model.
Distortion, relative illumination, chief ray angle, back focal length, modulation transfer data and the 2D/3D model are not carried in the published specification and are released per build on request.
Where a 168°; M12 Lens Earns Its Place
Four application patterns follow directly from the specifications above.
Blind-spot and surround coverage on vehicles
Cameras mounted on mirrors, bumpers or roof edges must cover the region a driver cannot see, often at less than a metre from the bodywork. A 168°; diagonal field keeps that near field inside the frame, and the aluminum barrel holds focus across the temperature swing a parked vehicle sees between a winter night and a summer afternoon.
Door entry and access panels
An entry camera has to see a face and the floor in front of the door in the same frame, and it usually faces weather while doing it. Small format, IP 67 sealing and the 650nm or 850nm filter choice cover the mechanical, environmental and night-channel requirements in one part.
Indoor overview and room monitoring
One camera covering a room replaces several narrow ones, provided the corners stay usable after correction. The lens is rated at 5MP while the sensor resolves 2MP, and that sampling headroom is what resampling and edge straightening consume before a wide field turns into soft corners.
Robotics, AGVs and equipment enclosures
Mobile platforms need a wide field for obstacle awareness without adding optics at every corner. All-glass construction matters in this case for a second reason: a plastic hybrid can drift out of focus as an enclosure heats up, and a sealed all-glass barrel holds the focus position the module was qualified at.
Choosing Between 168°; and 210°; Class Optics
The two wide-angle classes are not interchangeable, and the difference is best understood as what each one asks the rest of the module to do.
| Consideration | 168°; class (JSD2157) | 210°; class fisheye |
|---|---|---|
| Coverage geometry | Wide, shallow band on a 16:9 sensor | Approaches circular coverage of the frame |
| Image circle | 6.7mm, a small margin around the active area | Typically sized tight to the sensor diagonal |
| Mechanical envelope | φ17mm barrel, 22mm TTL | Often smaller and shorter, which limits resolution margin |
| Resolution margin | 5MP rating on a 2MP sensor | Frequently rated at the sensor's own resolution |
| Processing load | Moderate correction, stable geometry | Full projection unfolding required |
| Best fit | Vehicle blind spot, door entry, room overview | Panoramic capture and omnidirectional sensing |
When a project needs the full panoramic field, the ultra wide-angle lens range covers the fisheye models and their projection characteristics, and the mechanical trade-offs follow from that choice. The useful question to settle first is whether the image has to be geometrically usable as captured, or whether a projection step is part of the product plan.
Engineering Considerations Before You Commit
Four items decide whether a 168°; part integrates cleanly. None of them are hidden, but each one costs design time if it is discovered late.
Put the correction stage in the module plan. A field this wide is projected onto a flat sensor with geometric compression toward the edges. Either the module carries a correction stage, or the acceptance criterion has to allow the natural projection, and that call belongs in the plan before the housing is tooled rather than after the first image review. The JSD2157 is optimised for modules where a compact M12 envelope matters. Where uncorrected geometry is the priority, a longer focal length at a narrower field is the starting point, and that is a different selection conversation rather than a setting on this part.
Confirm the corner requirement, not the centre. Wide-angle modules are usually judged on the corner of the frame, where illumination and spot size are hardest to hold. Specify the acceptance threshold at the corner and the test distance, then confirm relative illumination and edge resolution data for the build.
Design the holder around the envelope. A φ17mm barrel sets the minimum bore of the front opening and 22mm total track length sets the front-to-sensor depth. Because the JSD2157 uses the M12 × P0.5 standard thread, one holder platform can carry other M12 parts in the range when a project needs a second field of view.
Settle the spectral configuration per project. The part supports 650nm and 850nm filter options, and the two are different decisions: an infrared-cut filter preserves colour reproduction under broadband light, while an infrared-corrected design keeps focus stable when the scene is illuminated by near-infrared energy. Neither follows automatically from the part number, and the wavelength band, illuminator, expected working distance and night-time acceptance criteria all belong in the specification before a configuration is fixed.
"Ask for the wavelength band and the filter arrangement, not for a one-word answer on infrared. The useful reply names the band, the configuration and the expected focus behaviour."
— JSD Optics engineering guidanceWhy Design Teams Bring This Problem to JSD Optics
Wide-angle modules rarely fail on the headline number. They fail on the interaction between the image circle, the mounting envelope and the correction budget, which is why the work starts from the sensor rather than from the focal length.
Sensor-first selection. The starting point is the image sensor and its diagonal, so the field of view, the image circle and the mount are matched before a housing is tooled.
Optical and mechanical data on request. Field of view triplets, relative illumination, chief ray angle, back focal length and the 2D/3D model are released per build rather than published in isolation.
Configuration work is part of the supply. Spectral filter arrangement, sealing level and focus-locking detail are engineering work items supported across standard and custom variants.
Volume production discipline. Design and manufacturing operate under ISO 9001 and IATF 16949 quality management systems.
A firm answer needs eight inputs: sensor model, required field of view with its tolerance, working distance, mechanical envelope limits, sealing and ingress requirement, illumination band, the environmental conditions the module has to survive, and the resolution the correction stage is expected to preserve. With those in hand, the response is a specific part and its data set rather than a range of possibilities.
❓ Frequently Asked Questions
How do I know whether a 168°; lens will cover the sensor?
Compare the image circle with the sensor diagonal before anything else. The JSD2157 projects a 6.7mm image circle, which covers a 1/2.8" sensor with a small margin around the active area. If the sensor diagonal is larger than the image circle, no amount of focus adjustment recovers the corners, and the correct response is a different part rather than a different setting.
What does the M12 S mount mean for a mechanical design?
M12 × P0.5 is a standard thread, so the holder and the focus-locking arrangement follow a familiar pattern and the same holder platform can be shared with other M12 lenses. The figures that constrain the housing are the φ17mm barrel diameter and the 22mm total track length, which together set the minimum bore and the front-to-sensor depth.
Does a 168°; field of view need software correction?
Yes, in most cases. A field this wide is projected with geometric compression toward the edges, so the module plan needs either a correction stage or an acceptance criterion that allows the natural projection. The JSD2157 carries a 5MP rating, which leaves sampling headroom for resampling and edge straightening without pushing the corners into a soft result.
Can the JSD2157 be used in an outdoor enclosure?
The part is rated IP 67, and the aluminum exterior with all-glass optics supports an operating range from −20°;C to +85°;C. For a project where the module also has to work under near-infrared illumination, the filter arrangement is confirmed against the illuminator wavelength and the expected working distance rather than assumed, because the infrared-cut filter decision and the infrared focus correction decision are independent.
Send the Specification to an Optical Engineer
Send the sensor model, the field of view with its tolerance, the mechanical envelope and the environment.
Or email us at info@jsdoptical.com
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