Short-wave infrared (SWIR) imaging has moved from a niche defense technology to a cornerstone of industrial machine vision — enabling engineers to detect defects, verify fill levels, sort materials, and inspect semiconductors entirely beyond what the human eye, or a standard camera, can ever see.
Most industrial cameras capture light in the visible spectrum — roughly 400 nm to 700 nm — and sometimes extend slightly into the near-infrared (NIR) range around 700 nm to 1,000 nm. SWIR cameras operate well beyond this window, typically covering 900 nm to 1,700 nm, and in the case of modern visSWIR sensors like those found in the Basler ace 2 X visSWIR series, spanning the full range from 400 nm all the way to 1,700 nm in a single sensor. This dramatically wider spectral sensitivity is not merely a technical curiosity — it unlocks a completely different way of seeing the physical world.
At SWIR wavelengths, many materials behave in ways that seem counterintuitive. Silicon — completely opaque under visible light — becomes transparent. Common plastics reveal internal structures. Moisture distribution across agricultural products becomes clearly visible. Subtle surface bruising on fruit, which looks flawless to the naked eye, shows up vividly. These properties make SWIR imaging essential in semiconductor manufacturing, food quality inspection, pharmaceutical production, recycling, and a growing number of other demanding industrial environments.
Watch our overview of SWIR imaging technology and its industrial applications.
What Is SWIR? Understanding the Spectral Range
The electromagnetic spectrum is divided into regions based on wavelength. The visible spectrum (approximately 400–700 nm) is what human eyes detect. Near-infrared (NIR) extends slightly beyond that, up to around 1,000 nm. Short-wave infrared (SWIR) picks up where NIR leaves off, occupying the 900 nm to 2,500 nm range — though most industrial SWIR cameras focus on the 900–1,700 nm window, where InGaAs (indium gallium arsenide) sensors perform most effectively.
Unlike thermal imaging (mid-wave infrared or MWIR, and long-wave infrared or LWIR), SWIR cameras do not depend on the heat signature of an object. Instead, they detect reflected or emitted light in the SWIR band, producing images that carry a spatial and textural quality far more similar to visible-light photography. This is one reason SWIR images integrate naturally into existing machine vision workflows — the data is intuitive to interpret and compatible with standard computer vision algorithms.
Key distinction: At surface temperatures above approximately 140°C, objects begin to emit light in the SWIR band — making SWIR cameras useful not only for reflective inspection tasks, but also for non-contact thermal monitoring of hot surfaces in steel production, glass manufacturing, and semiconductor furnace processes.
Conventional silicon-based CMOS and CCD sensors become insensitive beyond roughly 1,000 nm, which is why specialized sensor materials are required for true SWIR imaging. InGaAs has long been the industry standard for this spectral range, offering excellent quantum efficiency, good sensitivity, and — critically — no cooling requirement for most industrial machine vision tasks. Sony's SenSWIR™ platform, which powers Basler's ace 2 X visSWIR cameras, brings InGaAs technology into a compact, cost-effective industrial form factor that has significantly lowered the barrier to SWIR adoption across industries.
Why Industrial Engineers Choose SWIR Cameras
SWIR imaging solves specific problems that no other imaging technology addresses as effectively. The following are the core reasons engineers across industries are integrating SWIR cameras into their machine vision systems.
Subsurface Inspection Without Contact
Certain materials are translucent in the SWIR band even when they appear completely opaque under visible light. Silicon wafers are the most well-known example — SWIR cameras can image through the wafer to detect voids, cracks, inclusions, and alignment marks that would be invisible using standard cameras. Packaged electronics, encapsulated components, and opaque resin-molded products can similarly be inspected non-destructively in a fraction of the time required by alternative methods.
Material Discrimination and Sorting
Different materials absorb and reflect SWIR light differently based on their molecular composition. This allows SWIR cameras to distinguish between materials that look visually identical — a capability of profound value in recycling and waste sorting (separating plastic types that appear identical), food inspection (detecting foreign materials like stones among produce), and pharmaceutical production (identifying impurities or verifying substance identity).
Fill Level Detection Through Opaque Containers
SWIR light penetrates many otherwise opaque packaging materials — including certain plastics, papers, and cartons — making it possible to verify fill levels, detect air gaps, or confirm product presence without opening or disturbing the package. Pharmaceutical blister pack inspection, liquid fill lines, and sealed consumer goods all benefit directly from this capability.
Agricultural and Food Quality Analysis
Moisture content, sugar concentration, bruising, rot, and foreign body contamination are all detectable with SWIR imaging in ways that visible-spectrum cameras cannot match. A fruit that shows no surface damage whatsoever may have internal bruising clearly visible at 1,000–1,350 nm. Harvesters equipped with SWIR cameras can sort produce in real time based on actual internal quality rather than surface appearance alone.
Performance in Challenging Environments
SWIR imaging is considerably less affected by environmental scatter — fog, smoke, fine particulates, haze — compared to visible light cameras. This makes it useful in outdoor inspection scenarios, high-dust manufacturing environments, and applications where illumination conditions are inconsistent or difficult to control.
High-Temperature Process Monitoring
Objects above approximately 140°C begin to emit SWIR radiation, and those above 250°C emit enough to be detected reliably by standard SWIR sensors. This passive emission capability makes SWIR cameras valuable for monitoring molten metals, heated glass, semiconductor furnaces, and industrial soldering equipment — without the cost or calibration complexity of dedicated thermal cameras.
Industrial Applications at a Glance
Silicon wafer inspection, solder joint analysis, packaged IC defect detection, solar cell quality control, and electrode alignment in battery manufacturing.
Bruise detection on fruit and vegetables, moisture mapping, foreign body inspection, sugar content estimation, and real-time sorting of ripe versus unripe produce.
Blister pack inspection, substance verification, contamination detection, fill level validation in opaque containers, and tablet coating analysis.
Plastic type differentiation and sorting, detecting misclassified waste streams, and separating mixed materials that appear identical under visible light.
Defect detection in glass substrates, photovoltaic cell inspection from individual silicon blocks to full panels, and stress fracture analysis.
Non-contact monitoring of hot metal, glass, and semiconductor manufacturing processes; furnace inspection; and soldering quality assessment.
Basler ace 2 X visSWIR Cameras
As an authorized Basler distributor, Wilco Imaging carries the Basler ace 2 X visSWIR camera series — one of the most significant advances in accessible SWIR imaging in recent years. These cameras are built around Sony's SenSWIR™ InGaAs sensor platform and are designed to capture light across the full visible-to-SWIR spectrum, from 400 nm to 1,700 nm, within a single compact camera body.
The Basler ace 2 X visSWIR cameras are available with Sony IMX990 (1.3 MP), IMX991 (VGA), IMX992 (5.2 MP), and IMX993 (3 MP) SenSWIR sensors, covering a range of resolution requirements for area-scan machine vision tasks. Interface options include USB 3.0 and GigE. The cameras deliver up to 240 fps at VGA resolution and 131 fps at 5.2 MP — all within Basler's standard 29 mm × 29 mm ace 2 housing, one of the smallest footprints available for any visSWIR industrial camera.
A key engineering achievement in this series is the elimination of active cooling. InGaAs sensors are prone to pixel defects — visible as bright spots — that worsen at higher temperatures or longer exposures. Basler addresses this with two firmware-level features: Pixel Correction Beyond, which dynamically detects and corrects pixel defects in real time on the camera's FPGA without distorting image content; and Line Noise Reduction, which removes the horizontal banding noise characteristic of InGaAs sensors on the IMX990 and IMX991 models. The result is a cooler-free SWIR camera delivering image quality previously achievable only in larger, more expensive TEC-cooled systems.
All ace 2 X visSWIR cameras are supported by Basler's pylon software suite, providing out-of-the-box image acquisition, SDK integration, and driver support across Windows and Linux platforms.
Wilco Imaging also carries the broader Basler ace and ace 2 camera families, including NIR-optimized monochrome models such as the acA2040-90umNIR — a USB 3.0 monochrome camera optimized for near-infrared applications that serves as a cost-effective entry point where the full SWIR range is not required. Our team can help you determine which sensor and interface combination aligns best with your specific wavelength, resolution, and frame rate requirements. Browse our full Basler camera collection here.
Kowa HC-SW Series SWIR Lenses
A SWIR camera is only as capable as the optics paired with it. Standard industrial lenses are designed and optimized for the visible spectrum — many actually filter out infrared wavelengths entirely. At SWIR wavelengths, conventional glass formulations suffer from significant chromatic aberration, focal shift, and reduced transmission, all of which degrade image quality and measurement accuracy.
Wilco Imaging carries the Kowa LM HC-SW series — a purpose-built line of 1" format SWIR lenses engineered specifically for NIR and short-wave infrared imaging applications. These lenses incorporate special optical coating technology that maintains high transmission across a spectral range from 800 nm to 2,000 nm, making them suitable for the full operating range of InGaAs-based cameras including the Basler ace 2 X visSWIR series.
| Model | Focal Length | Format | Spectral Range | Price |
|---|---|---|---|---|
| Kowa LM8HC-SW | 8 mm | 1" | 800 – 2,000 nm | $1,381.00 |
| Kowa LM12HC-SW | 12 mm | 1" | 800 – 2,000 nm | $1,381.00 |
| Kowa LM16HC-SW | 16 mm | 1" | 800 – 2,000 nm | $1,381.00 |
| Kowa LM25HC-SW | 25 mm | 1" | 800 – 2,000 nm | $1,381.00 |
| Kowa LM35HC-SW | 35 mm | 1" | 800 – 2,000 nm | $1,381.00 |
| Kowa LM50HC-SW | 50 mm | 1" | 800 – 2,000 nm | $1,381.00 |
The Kowa HC-SW series covers focal lengths from 8 mm through 50 mm, offering field-of-view flexibility for a wide range of inspection geometries — from wide-angle conveyor inspection to narrow-field precision defect detection. All models are 1" format, matching the optical format of the Basler ace 2 visSWIR sensors and ensuring full-frame coverage without vignetting.
A key optical challenge in visSWIR imaging — where a single lens must maintain focus across both the visible and SWIR wavelengths — is focus shift: different wavelengths refract slightly differently through standard glass elements, causing the focal point to shift along the optical axis. The Kowa HC-SW lenses are designed to minimize this chromatic shift across their specified spectral range, enabling sharp image acquisition without constant refocusing as spectral conditions change.
Wilco Imaging also carries the Computar ViSWIR Hyper APO Series — additional SWIR-compatible lens options designed for visible-to-SWIR imaging with apochromatic correction. View the Computar ViSWIR lineup here.
Building a Complete SWIR Vision System
Selecting a SWIR camera and lens is only the beginning. A complete SWIR machine vision system typically requires coordinated selection across several components: the camera (sensor type, resolution, interface, and frame rate), the lens (focal length, format, and spectral correction), SWIR-wavelength illumination, optical bandpass filters to restrict the spectral range to the wavelength of interest, interface cards compatible with the camera, and software for image acquisition, processing, and integration into existing manufacturing systems.
At Wilco Imaging, we carry the products and have the applications expertise to help you assemble a system that fits your requirements. Whether you are qualifying a Basler visSWIR camera for semiconductor wafer inspection, specifying Kowa HC-SW lenses for a food sorting line, or evaluating whether SWIR imaging is the right technology for a new inspection challenge, our team is available to guide you from sensor selection through system integration.
Note on export classification: Basler ace 2 X visSWIR cameras are classified as dual-use products under ECCN 6A003.b.4.a and Regulation (EU) 2021/821. Export licenses may be required depending on the destination country. Contact us for guidance on your specific situation.
As a Lore Technology company based in West Sacramento, California, Wilco Imaging serves customers across North America and ships internationally on EX WORKS terms. Our in-stock items typically ship same-day from our Sacramento warehouse. We also offer custom camera sensor services — including sensor glass removal and filter installation — for applications that require bare-sensor access or custom spectral filtering.
Questions about SWIR cameras, Kowa SWIR lenses, or system configuration? Our team is ready to help.
