Industrial Infrared (IR) Lighting for Machine Vision
Infrared illumination sees past what visible light cannot: it passes through materials that look opaque to the human eye, without ever disturbing a human operator standing next to the line.
The Physical Problem
A vision system often needs to inspect a feature that visible light simply cannot reach — fill level through a dark plastic bottle, a weld seam under a coating, print hidden beneath an opaque film. Under standard white or colored illumination, the outer material absorbs the light before it ever reaches the feature of interest, and the camera sees nothing but a uniformly dark or saturated surface. Adding more visible light doesn't help: the material blocks it regardless of intensity.
The Optical Solution
A material's opacity is wavelength-dependent, not absolute. Many carbon-loaded plastics and dark inks that absorb almost all visible light (400-700nm) become significantly more transmissive in the near-infrared band, typically around 850nm or 940nm — the same physical effect that lets a TV remote's IR beam pass through a visibly opaque black plastic bezel. Illuminating with IR LEDs at these wavelengths lets the camera's sensor (which remains sensitive slightly beyond the visible range) capture what's hidden beneath the surface. As a secondary benefit, IR sits outside the 380-740nm band the human eye perceives, so an IR-lit inspection station doesn't add visible glare or flicker for nearby operators.
Wiring & Integration Recommendations
IR modules wire onto the same standard M12 pinout as our other lights. Because IR penetration often calls for higher drive current, synchronize the source in strobe/overdrive mode rather than continuous: it freezes the moving part and confines LED heating to the instant of the camera trigger.
Not Sure About the Optical Result?
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Describe your inspection challenge and one of our engineers will recommend the right optical approach.
Recommended Lighting Formats
Integration Tools
Application Notes & Optical Challenge Resolution
Three engineering application notes showing how the right optical principle — not a different camera or software — resolves the inspection challenge.
Industrial Context
Food & Beverage / PackagingOptical Problem
Saturating glare on glossy plastic film during seal inspection.
Solution & Geometry
630nm Diffuse Dome Lighting (omnidirectional light).
Physical Result
Elimination of the specular hot spot and light homogeneity above 90%.
Industrial Context
Pharmaceutical / VialsOptical Problem
Liquid fill-level inspection through an opaque amber glass vial.
Solution & Geometry
850nm Infrared Backlight, transmitted through the tinted glass.
Physical Result
Optimal transmittance through the liquid, clean contrast on the meniscus.
Industrial Context
Metalworking / AutomotiveOptical Problem
Reading a laser-marked Data Matrix (DPM) code on a machined metal surface.
Solution & Geometry
Darkfield Grazing Light + Crossed Polarization.
Physical Result
Cancellation of directional glare, clean separation of the code's micro-relief.
Application notes based on real physical and optical principles — exact outcomes depend on your configuration and are validated during a lab sample test.