Inspecting Automotive Paint Inspecting Automotive Paint E ffective inspection of automotive paints and finishes requires a lighting environment that produces strong luminance edges which can be seen in reflection from the surface of an automobile. Paint defects such as embedded dirt, runs, sags, and dents reflect light from many different angles. For a defect to be visible to an inspector, the defect and its immediate background must have different luminances. To achieve this, surfaces in inspection rooms must have differences in luminance that can be seen in reflection.
Inspectors find more defects in darker paints than in lighter paints.
The pigments of the lighter paints reflect more ambient illuminance, reducing the contrast of the specular highlights on the defect. In an optimal inspection environment, the walls, ceiling, and floor are covered with a strong luminance pattern, ensuring that defects on the vehicle surface will always be close enough to a luminance edge to be detected. The larger the reflected highlight, the more likely inspectors are to find defects. Highlight size depends on the angular distance from the lamp image.