JSD1330 13mm M12 Lens - 5MP, 8.2mm Circle, Low Distortion
JSD1330: A 13mm M12 Lens That Turns Working Distance Into Field of View
A 13mm M12 lens with a Ø8.2mm image circle and a 5MP rating, measured distortion below −0.07%, for 1/2.7" sensors in machine vision and biometric modules.
Key takeaway: The JSD1330 is a 13mm fixed focal length M12 lens whose Ø8.2mm image circle covers a 1/2.7" sensor with roughly 28% of margin. Measured distortion sits below −0.07%, which keeps the calibration model small. The φ14mm barrel and 21.87mm total track length set the housing, and the focusing arrangement is the item to settle early, because depth of field at these standoffs is only a few millimetres deep.
Why a 40mm Field at Two Working Distances Cannot Come From One Fixed Focus
A small 2MP sensor and a small field of view should be a simple brief. This one produces the most rework of any small-format project, because the field of view is not a property of the lens on its own. It is a property of the lens and the distance it sits from the object, and that pair is what has to be designed together.
The arithmetic is short. Magnification is the ratio of the working distance to the focal length, so the projected field is the sensor size multiplied by that ratio. A 1/2.7" sensor at 1920 × 1080 with a 2.9µm pixel pitch holds an active area of roughly 5.57mm by 3.13mm. To project a 40mm wide field onto that area, the lens has to deliver a magnification of about 7.2 times. At an 85mm working distance that points to a focal length in the 10mm to 13mm band. At a 50mm working distance the same 40mm field would demand roughly 8mm instead.
One lens therefore cannot hold the same field of view at both distances. A 13mm lens at 85mm outlines about 36.6mm by 20.6mm, within 10% of the intended 40mm. The same lens at 50mm outlines a field about 40% narrower, and only a re-focus or a different focal length brings it back. That is a geometry result rather than a limitation of any one part, and it belongs in the requirement before supplier conversations start, because it decides the whole mechanical concept.
Three assumptions that cost design time
A fixed focus lens will cover both distances. It will not, unless the two distances are close enough that the change in magnification stays inside the tolerance on the field. On a 13mm lens, 85mm and 50mm are far enough apart to sit outside that tolerance.
The thread size sets the working distance. M8 and M12 describe mounting hardware, not optical reach. A large thread carries a large image circle and a longer focal length, but it never determines how far the lens can stand from the object.
The field of view has no aspect ratio. A requirement written as 40mm by 30mm is 4:3, while a 1920 × 1080 sensor is 16:9, so a 40mm wide field on that sensor is about 22.5mm tall. Either the 30mm is a region of interest inside the frame, or the target field needs a different sensor format.
What the 13mm option delivers in that arrangement, and what has to be settled before a housing is drawn, comes down to the checks below.
What 13mm and a Ø8.2mm Image Circle Actually Deliver at 85mm
Three numbers carry the part, and each one closes a question a design team is already asking.
The 13mm focal length. This is a long focal length for the M12 platform, which is what makes a mid-range standoff with a narrow field workable. The published field of view of the JSD1330 is 23° horizontal on a 1/2.7" sensor, quoted in the library as 26° diagonal, 23° horizontal and 13° vertical. Those angles belong to the format they were quoted on: a larger format opens every one of them, so the figure is re-checked against the actual sensor rather than carried across.
The Ø8.2mm image circle. A 1/2.7" sensor at 1920 × 1080 resolves to roughly 6.39mm of diagonal, so a 6.39mm diagonal sits inside a circle 1.8mm wider. That difference is what absorbs mounting tolerance, and it is the reason a larger sensor means a different part rather than a different setting. Between the two, the circle is the constraint that cannot be adjusted after the fact.
Distortion below −0.07%. This is a measured band rather than a marketing claim. In a measurement or positioning system it counts twice: straight lines in the scene stay closer to straight in the image, and the calibration model carries a smaller correction to absorb. Fewer correction terms mean fewer coefficients that can drift from one build to the next.
The 1G3P construction is the last piece of the picture. One glass element sets the reference, and three moulded aspheres do the correction work inside a short barrel. That is how a 13mm focal length and an Ø8.2mm image circle fit into a φ14mm envelope and a 21.87mm total track length, which is the space the rest of the module has to share.
Start with the pixel pitch, not the format name
Sensor format names are approximate labels. Two parts sold as 1/2.7" can differ in active area, and everything above is expressed in millimetres. Pull the pixel pitch from the sensor data sheet, multiply by the active pixel count, and confirm the diagonal before the lens is ordered. That single step turns a format name into the number the optical calculation needs, and a mismatch here surfaces late, once the housing has already been machined around the wrong diagonal.
JSD1330 Specifications and What Each Number Changes
The table below is the working specification for the JSD1330, paired with the consequence of each figure so the numbers can be carried straight into a mechanical model.
| Parameter | Specification | Design impact |
|---|---|---|
| Part number | JSD1330 | — |
| Focal length | 13mm | Long reach for the M12 platform; makes a narrow field possible at a mid-range working distance |
| Aperture | F3.0 | Sets the exposure budget and the depth of field; light availability is confirmed against the illuminator |
| Field of view | 26° D / 23° H / 13° V | Sets coverage in all three axes, so a diagonal figure alone is not enough to model the frame |
| Image circle | Ø8.2mm | Wider than the 1/2.7" diagonal, which is where mounting tolerance and the corners are covered |
| Resolution | 5MP | Rated above the 2.07MP required, so sampling headroom survives resampling |
| Distortion | Measured <−0.07% | Test chart distance, field definition and acceptance threshold are agreed per project |
| Optical construction | 1G3P (1 glass, 3 plastic elements) | Glass reference plus moulded aspheres hold geometry in a short barrel |
| Mount | M12 S mount | Standard holder platform shared with other M12 parts in the range |
| Barrel outer diameter | φ14mm | Sets the minimum bore of the front housing opening |
| Total track length | 21.87mm | The front-to-sensor length the mechanical engineer needs first |
| Ingress rating | No rating published | Points the part at enclosed housings rather than exposed outdoor mounting |
| Filter options | 650nm and 850nm IR filter available | Confirmed per project; the filter choice follows the illuminator band |
Two notes on reading the table.
The field of view triplet and the image circle are quoted for the 1/2.7" format, and both move with the sensor. Treat them as per-build values rather than constants.
Relative illumination, chief ray angle, back focal length, modulation transfer data and the 2D and 3D models are not carried in the published specification. They are released per build on request, and the distortion figure is always quoted with its test conditions.
The published total track length and the value carried in the optical library differ by a fraction of a millimetre. On a housing drawing that difference is real metal, so the reference is the drawing of the build being purchased — worth asking for the revision that matches the order.
Where a 13mm M12 Lens Earns Its Place
Four application patterns follow from the figures above, and all four share the same starting point: a modest working distance measured in tens of millimetres, and a field measured in tens of millimetres as well.
Machine vision inspection stations
An inspection camera reading features, edges or fiducials at a fixed standoff needs a field that does not move when the station is serviced. A low distortion band reduces the correction the inspection software has to apply, and the 5MP rating leaves headroom for the resampling that edge detection consumes. Where a station runs at a fixed distance, the focus is set once at build and locked.
Biometric and iris recognition modules
Iris imaging is a narrow field problem at a short standoff, and the geometry has to stay stable across thousands of captures. The Ø8.2mm image circle covers the sensor with margin, and the low distortion band keeps the iris ring a faithful shape rather than one that has to be un-warped before matching. The illuminator band decides the filter configuration for the build.
Precision positioning and small-part assembly
Picking and placing small parts needs the field to be small and resolution to hold at the edge of it. Alignment targets often sit at the frame edge rather than on the axis, and the resolution rating is what keeps the corner usable when a target lands there.
Fixed-distance gauging and test fixtures
Gauging fixtures repeat the same measurement at the same distance, so the focus position is a build parameter rather than a user setting: it has to be defined by the incoming tolerance and the repeatability of the mount, then locked. Here, one holder platform can also carry other M12 parts in the range when a fixture is later asked for a second field.
Choosing Between 13mm, 11.08mm and 8mm Focal Lengths
The useful comparison is not which lens is better, but which one matches the working distance and the field the project actually needs. Focal length is the one lever that moves both at the same time, so it is the first value to fix.
| Consideration | 13mm (JSD1330) | 11.08mm class | 8mm class |
|---|---|---|---|
| Mount | M12 | M8 | M12 |
| Image circle | Ø8.2mm | 1/2.5" class | 1/2.5" class |
| Field at a long standoff | Narrowest of the three | Slightly wider | Clearly wider |
| Field at a short standoff | Narrows by about 40% against the long standoff | Narrows by the same ratio | Closest to a 40mm field at 50mm |
| Resolution rating | 5MP | 5MP | 5MP class |
| Distortion band | Measured <−0.07% | Below 0.4% | Confirm per build |
| Focus locking | Arrangement confirmed per build | Confirm per build | Confirm per build |
| Best fit | Mid-range standoff with a narrow field and geometric fidelity | Similar standoff where the small thread is a hard constraint | Short standoff where the wider field is the priority |
The table reads in one direction only. Where the geometry is settled at a mid-range standoff and the field must stay narrow and faithful, the 13mm option is the starting point. Where an existing M8 holder is a fixed constraint, the choice moves to the 11.08mm class and the field requirement gets re-stated around the smaller thread. Where the field has to be about 40mm at a 50mm standoff, the focal length lands near 8mm, and the coverage of a 1/2.7" diagonal has to be confirmed on the actual build before the design is frozen. Browsing the machine vision lens range sorted by focal length shows the same trade faster than a list of part numbers.
Engineering Considerations Before You Commit
Five items decide whether this part integrates cleanly. Each one is settled by a question the supplier can answer, and each one costs design time if it is discovered after the housing is cut.
Fix the distortion test conditions, not just the number. A distortion figure without its test chart distance, field definition and acceptance threshold cannot be compared between suppliers or between builds. Agree the conditions first, then quote the measurement against them, and confirm that the band and the acceptance limit are expressed the same way.
Reconcile the aspect ratio before the field is frozen. A 4:3 field requirement on a 16:9 sensor leaves the height unresolved. Decide whether the requirement is the full field of view or the region of interest inside it. The answer changes the focal length by a substantial margin, and it is the single most common source of a late change in a small-field design.
Settle the focus mechanism early. At an 85mm standoff and F3.0, the usable depth of field is only a few millimetres deep, and at a 50mm standoff it is narrower again. A fixed focus part works when incoming tolerances and mounting repeatability can be held inside that window; where they cannot, a focus adjustable version with a locking screw is the route to take. Either way the locking detail belongs in the mechanical drawing rather than in a verbal agreement.
Design the holder around the envelope. The φ14mm barrel sets the minimum bore of the front opening, and 21.87mm total track length sets the front-to-sensor depth the module has to reserve. Because the mount is the M12 S standard thread, one holder platform can carry other M12 parts in the range when a project needs a second field of view at a second standoff.
Confirm the filter configuration for the build. The part supports 650nm and 850nm IR 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 lit by near-infrared energy. Neither follows from the part number, so the wavelength band, the illuminator, the expected standoff and the acceptance criteria belong in the specification before a configuration is fixed.
"At F3.0 and an 85mm standoff, depth of field runs a few millimetres deep. The focus position is a tolerance on the drawing, and so is the way it stays there."
— JSD Optics engineering guidanceWhy Design Teams Bring This Problem to JSD Optics
Small field modules rarely fail on the headline number. They fail on the interaction between the image circle, the standoff and the focus arrangement, so a supplier reply is only useful when it starts from the sensor and its diagonal — the point where the field of view, the image circle and the mount can be matched before a housing is drawn — rather than from a focal length list.
Optical and mechanical data on request. Field of view triplets, relative illumination, chief ray angle, back focal length, distortion measured against agreed test conditions and the 2D and 3D models are released per build rather than published in isolation.
Configuration work is part of the supply. Filter arrangement 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 distances, mechanical envelope limits, ingress requirement, illuminator band, the environmental conditions the module has to survive, and the resolution the correction stage is expected to preserve. With those in hand, the reply is a specific part and its data set rather than a range of possibilities.
❓ Frequently Asked Questions
How do I check that a 13mm M12 lens covers a 1/2.7" sensor?
Compare the image circle with the sensor diagonal before anything else. The JSD1330 projects a Ø8.2mm image circle, while a 1/2.7" sensor at 1920 × 1080 with a 2.9µm pixel pitch needs about 6.39mm of diagonal, so there is roughly 28% of margin. If the sensor diagonal were larger than the image circle, no amount of focus adjustment would recover the corners, and the correct response would be a different part rather than a different setting.
What does the M12 S mount mean for a mechanical design?
M12 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 in the range. The figures that constrain the housing are the φ14mm barrel diameter and the 21.87mm total track length, which together set the minimum bore and the front-to-sensor depth.
Does a distortion figure below −0.07% remove the need for calibration?
A measurement system still needs calibration at any distortion level. What a low band changes is the size of the correction the model has to carry: fewer terms, smaller residuals, and less drift between builds. Agree the test chart distance, the field definition and the acceptance threshold with the supplier first, so the figure can be compared against the build being purchased.
Can one 13mm lens hold the same field of view at two working distances?
Magnification scales with working distance, so the projected field scales with it. A lens set for a 40mm field at an 85mm standoff outlines a field roughly 40% narrower at 50mm. Serving both distances calls for a focus adjustable lens with a locking screw, or two fixed lenses each set for one standoff.
Send the Specification to an Optical Engineer
Send the sensor model, both working distances, the field of view with its tolerance, and the mechanical envelope.
Or email us at info@jsdoptical.com
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