Raking Light
Quick answer: Raking light is lighting aimed across a surface at a very shallow angle to reveal texture and defects by casting tiny shadows and highlights.
What it means
When light skims across paint at a low angle, even small height differences show up clearly. Swirls, sanding marks, holograms and unlevelled coating patches become visible because the grazing light exaggerates their contrast. Hand-held, high-CRI LEDs and slim panel lights are commonly used for this inspection technique.
Why it matters
- Defect finding: exposes swirls, haze, holograms, dust nibs and orange peel that overhead lighting can miss.
- Coating quality: makes high spots, overlaps and rainbowing visible during the levelling window.
- Consistency: helps verify correction work panel by panel before protection is applied.
- Colour accuracy: high-CRI light shows true finish without colour casts that can hide issues.
Where you’ll see it
Paint correction stages, ceramic coating application and final QC, usually in a controlled indoor bay with adjustable lights.
Context
Car Paint Protection; Ceramic coatings; Paint correction
Common mistakes
- Relying on bright overhead light only, which flattens defects rather than revealing them.
- Using low-CRI torches that hide fine marring or shift colour.
- Holding the light too close and on-axis, blowing out highlights and masking texture.
- Not changing angles or viewing distance, so overlaps and edges are missed.
- Trusting a phone torch for final QC – it is rarely bright or accurate enough.
Written by Danny Argent. Last updated 07/11/2025 14:45