JSD2916 Fisheye Lens for Sony IMX678: 190° FOV, BBAR & IR-Cut for Clean 4K
JSD2916 Fisheye Lens for Sony IMX678: What to Specify for a Clean 4K Panoramic Image — BBAR Coating and IR-Cut Filter, Explained
On a 4K panoramic camera built around the Sony IMX678, the sensor is rarely the component that decides image quality — the glass in front of it is. The IMX678 is a 1/1.8″ STARVIS 2 sensor selected for low-light sensitivity; the fisheye lens in front of it has to convert that sensitivity into clean footage while gathering light from nearly every direction at once.
That trade-off surfaced recently as a concrete buyer request: an engineer evaluating the JSD2916 — an 8MP UHD fisheye lens designed for the Sony IMX678 — asked whether it could be supplied as a sample with broadband anti-reflection (BBAR) coating and an IR-cut filter. It can. The real question is configuration, not availability. This guide explains what the two options change in the final image and how to specify them correctly on an IMX678 platform.
Key takeaway: The JSD2916 fisheye lens can be supplied with BBAR coating and an IR-cut filter, so the real decision on an IMX678 platform is configuration, not availability. BBAR suppresses the flare, ghosting, and edge color shift that a 190° field of view invites, while a fixed IR-cut filter locks in accurate daylight color for color-only systems. Day/night cameras should instead order the lens without a fixed filter and control IR via an external switchable ICR mechanism.
1. The Problem Nobody Warns You About: Wide-Angle Light Is Brutal on Image Quality
A fisheye differs from a conventional security lens in how it collects light. With a 190° diagonal field of view, the front element is continuously exposed to sunlight, streetlights, headlights, and reflective surfaces that a narrow-angle optic would never encounter. That exposure produces three measurable image defects:
Flare and ghosting, where bright sources inside or near the FOV scatter off internal surfaces and lay veiling glare or ghost images over the scene;
Reduced micro-contrast, as scattered light erodes the shadow detail a low-light sensor depends on, even when no ghost is visible;
Edge color shift, because light entering at glancing angles refracts differently through each optical surface and tints the periphery of the frame.
None of these defects originate in the sensor. On a STARVIS 2 platform they are purely optical, and they intensify as more light sources enter that extreme field of view. This is why the coating and the IR-cut filter — routinely treated as afterthoughts on a datasheet — are decisions best made at the start of the design, not after the first outdoor test footage.
2. Why BBAR Coating and an IR-Cut Filter Actually Matter
Broadband anti-reflection (BBAR) coating
Every air-to-glass surface reflects a small fraction of incident light. Across the eight elements of a lens like this, those reflections accumulate into the flare paths described in section 1. A broadband anti-reflection coating suppresses reflection across the visible spectrum — rather than at a single wavelength — and on a wide-angle optic that carries three specific consequences: higher transmission for night scenes where every photon reaching the IMX678 counts; the removal of flare and ghosting from in-frame streetlights and headlights; and steadier color out to the frame edges, where uncoated optics typically drift.
The IR-cut filter
The IMX678 senses well beyond the visible range into near-infrared. Left unfiltered, that IR light desaturates foliage, shifts fabric tones, and flattens the entire scene into a washed, low-contrast image. An IR-cut filter blocks the near-IR band so the sensor records only what the human eye sees — the correct setup for a color daylight camera, which is precisely what a request for a lens "with IR-cut filter" implies. Whether that filter should be bonded permanently into the lens or moved out of the path at night is a separate decision, handled in section 5.
3. The Solution: JSD2916 — A Fisheye Lens Built Around the IMX678
The JSD2916 is an 8MP-class fisheye lens developed for 4K UHD sensors in the 1/1.8″ class, of which the IMX678 is the reference. Each specification below is stated with the design consequence it delivers.
| Parameter | JSD2916 Spec | Design Impact |
|---|---|---|
| Projection | F-θ (equidistant) | Preserves angular proportions across the frame — the basis for dependable dewarping and stitching |
| Focal length | 2.9 mm | Captures an entire scene on a single sensor |
| FOV (D/H/V) | 190° / 158° / 83° | Near-180° situational awareness from one camera |
| Aperture | F/1.6 | Bright optic that feeds the IMX678's STARVIS 2 low-light response |
| Distortion | F-θ residual 4.09% | Low deviation from the ideal fisheye model, simplifying dewarp math |
| Construction | 5G3P (5 glass + 3 plastic) | Glass elements anchor focus through outdoor temperature swings |
| Image circle | 1/1.7″ (Ø9.2 mm) | The 1/1.8″ IMX678 sits inside with corner margin |
| Resolution headroom | Supports up to 12MP | Drives the 8MP/4K IMX678 at full sensor resolution |
| Mount | M12 | Standard industrial threading, quick to integrate into dome and bullet housings |
| Size | φ22 mm / 27.5 mm TTL | Compact enough for discreet or space-constrained cameras |
| Environmental | IP67 rated | Dust-tight with protection against temporary immersion |
On a 1/1.8″ format the IMX678 measures roughly 8.9 mm on the diagonal and sits fully inside the lens's 9.2 mm image circle, so corner illumination stays clean with no dark edges across the usable field. The 190° diagonal is specified on that native 1/1.7″ circle, meaning the delivered FOV on the IMX678 runs marginally below 190° — a difference that only matters when a coverage minimum is written to the last degree.
4. Where This Configuration Earns Its Keep
Four system types benefit most from the BBAR-and-IR-cut build, for different reasons:
360° and panoramic IP surveillance. One JSD2916 on one IMX678 replaces the multi-camera coverage a perimeter or open area would otherwise need. Here the BBAR coating does work that is easy to underestimate: a ghost or flare streak that appears once in a narrow frame reappears at every point of a stitched 360° view and is far harder to mask.
People counting and heat mapping (AI vision). These pipelines dewarp the fisheye into a top-down or corridor view, then track objects frame to frame. The F-θ mapping keeps pixel-per-degree uniform, so trajectories and counts stay consistent across the image rather than skewing toward the edges.
Outdoor dome and bullet cameras. A fixed IR-cut filter is what keeps foliage and signage colors accurate in a color daylight system mounted in a sealed, IP67-class housing. Combined with the five-glass construction, the build holds both focus and color through seasonal weather.
Robotics, smart home, and IoT vision. The φ22 mm M12 barrel fits a tight mechanical budget while returning a 190° situational view from a single module — enough awareness to skip a mechanical pan-tilt assembly.
5. Fixed IR-Cut vs. Switchable: Which Configuration Should You Ask For?
This is the point that separates a smooth sample run from a wasted one, so it deserves to be stated plainly.
If the camera is a pure color daylight system — no IR illumination, no black-and-white night mode — specify a fixed IR-cut filter bonded into the lens. It has no moving parts, adds no actuator, and guarantees accurate color in every frame at a lower cost.
If the camera switches to IR night mode, where an 850 nm or 940 nm illuminator takes over after dark, the filter must leave the optical path at night. That requires an external IR-cut filter removable (ICR) mechanism built into the camera module, so the lens should be supplied without a fixed filter.
A note on wavelength for the fixed-filter path: a common visible-only cut sits near 650–700 nm and suits most daylight applications. A day/night response that must also pass 850/940 nm IR is a different filter specification and changes the lens build, so it should be raised before the sample BOM is set rather than after.
6. Engineering Considerations for Your IMX678 Module
Three points are worth settling before a sample is locked in:
Thread, flange, and back focal distance. The φ22 mm barrel uses an M12 thread; confirm thread depth and back focal expectations in the housing, then re-verify back focal with the IR-cut filter bonded in place — the added glass shifts the optical path and can move the focus plane.
Projection model in firmware. Because the JSD2916 uses F-θ mapping with a 4.09% residual, the dewarp and stitching model is well behaved — but only if the projection parameters are logged in firmware notes so calibration stays consistent across units.
Sample validation. When the sample arrives, test it in the lighting that actually stresses the optic: a streetlight in frame at night, low sun near the FOV edge, and a bright interior scene in daylight. Those three conditions expose any coating shortfall faster than any lab chart.
7. Why Work With the Team Behind the Spec
JSD Optics develops and manufactures imaging lenses for camera module manufacturers, and this is where that role becomes visible in practice. A configured JSD2916 sample carries more than the optic itself:
Coating and filter options are standard, not specials. BBAR coating runs in the normal manufacturing flow, and the IR-cut option can be fixed-bonded or omitted for ICR designs — which keeps the distance from inquiry to tested sample short.
Sensor-aware matching. The engineering team validates the pairing against the actual IMX678 format — image circle, FOV, and flange — rather than shipping a generic part and letting integration absorb the risk.
Data ships with the sample. MTF curves and a CAD drawing are provided so the design can be validated in simulation before any production spend, with ISO 9001 and IATF 16949 quality systems governing the build.
❓ Frequently Asked Questions
Q: What is the JSD2916 fisheye lens used for?
A: A 4K UHD fisheye lens for 1/1.8″ sensors such as the Sony IMX678, used in 360°/panoramic IP surveillance, AI people counting, robotics, and IoT vision — anywhere one sensor must cover a near-190° scene.
Q: Does the JSD2916 work with the Sony IMX678 sensor?
A: Yes. The IMX678's ~8.9 mm diagonal sits fully inside the lens's Ø9.2 mm image circle, giving clean corners with a safety margin.
Q: Why does broadband anti-reflection coating matter on a fisheye lens?
A: A fisheye collects light from nearly every direction, so streetlights, sunlight, and headlights readily scatter into flare and ghosting. BBAR suppresses those reflections, raising night transmission and protecting daylight contrast and color.
Q: Should this fisheye lens be ordered with an IR-cut filter or without?
A: For a color-only daylight system, use a fixed IR-cut filter in the lens. For a day/night camera with an IR illuminator, order without a fixed filter and control the cut via an external ICR mechanism.
Q: What resolution can the JSD2916 support?
A: Up to 12MP, so it drives the 8MP/4K IMX678 at full sensor resolution with headroom.
Q: Is the JSD2916 suitable for outdoor cameras?
A: Yes. Five glass elements hold focus through temperature swings, and the IP67 rating suits dust-tight, weatherproof dome and bullet housings.
Q: How do I request a sample with a specific coating and filter?
A: Contact the JSD optical engineering team with the sensor (IMX678), whether the system needs a fixed IR-cut filter or an ICR setup, and the target cut wavelength (a 650–700 nm visible-only cut is typical). MTF data and a CAD drawing are provided with the sample.
Ready to Spec Your Sample?
Contact the JSD optical engineering team to configure your JSD2916 sample with BBAR coating and the correct IR-cut or ICR filter.
Or email us at info@jsdoptical.com
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