Surface inspection with machine vision detects scratches, cracks, pits, stains, inclusions, roughness variations, and surface finish defects on manufactured components at production speed. The ability to detect a specific surface defect depends entirely on the illumination technique: darkfield lighting reveals surface relief and scratches, coaxial lighting detects contrast variations on flat reflective surfaces, diffuse lighting provides uniform images of curved or uneven surfaces, and structured light enables 3D surface mapping. RODER Vision LED illuminators for surface inspection are available in ring, bar, dome, flat dome, and coaxial configurations, covering all major surface inspection geometries and material types. Applications include metal surface quality control in automotive and aerospace, plastic and rubber moulded component inspection, glass surface inspection, paper and film web inspection, and semiconductor wafer and display panel surface analysis.

How darkfield (low-angle) illumination exploits grazing incidence to reveal scratches, cracks, engraving, and surface texture on metals, glass, and plastics.