In detailing, three figures decide whether you'll see defects or discover them with the client, in direct sunlight: CRI, color temperature, and the number of lumens. In that order of importance.
The values to aim for, right away: CRI greater than 90, 5,500 to 6,500 K, and 750 to 1,000 lumens per m². Below that, you're working with a handicap that neither the polisher nor the product can compensate for.
CRI: Color Fidelity
The Color Rendering Index measures how accurately a lamp renders colors compared to daylight. The scale goes up to 100.
- CRI 70 to 80: sufficient for moving around, unusable for inspection. Reds and burgundies are particularly poorly rendered — a defect on a red car body becomes invisible.
- CRI 80 to 90: adequate for a mechanical workshop.
- CRI greater than 90: the threshold for detailing. This is where micro-scratches and differences in shine become visible again.
A figure to be aware of: classic workshop fluorescent tubes often peak around 70 to 80. Many detailers think they have a power problem when they actually have a color rendering problem.
Color Temperature: Neither Yellow Nor Blue
Expressed in Kelvin, it describes the hue of white light.
| Temperature | Appearance | Use |
|---|---|---|
| 2,700 – 3,000 K | Warm, yellow | Living room. Crushes defects, to be avoided. |
| 4,000 K | Neutral warm | Office, retail. |
| 5,500 – 6,500 K | Daylight white | Detailing, quality control. |
| Beyond 7,000 K | Bluish | Fatigues the eyes, distorts cool tones. |
The reason is simple: your client will judge the car outdoors, in daylight. It's best to work under the same conditions.
Lumens: Quantity, Once Quality Is Acquired
A perfect CRI with too little light is useless. In detailing, we aim for 750 to 1,000 lumens per m², which is double that of a DIY garage. For a 40 m² bay, this represents 30,000 to 40,000 lumens.
But pay attention to what "distributed" means: this is where the hexagonal grid changes the game. Two 20,000 lumen projectors create two spots and harsh shadows; the same quantity spread out in a grid creates a continuous blanket, with no shadow areas when you lean over a hood.
Why Defects Only Appear at Certain Angles
A hologram or micro-scratch is only visible when the light source reflects off the bodywork at a specific angle. With a single source, you have to move around the vehicle and tilt your head. With a grid that covers the entire ceiling, every point on the bodywork has a source above it, and the useful angles are multiplied.
This is also why the recommended density in detailing is 0.80 hexagons per m², while a garage is content with 0.55: it's not just a question of brightness, it's a question of reflection angles.
How to Check a Product Sheet
- The CRI must be announced, with its value. "High CRI" without a number means nothing.
- The color temperature must be unique and stable. A panel that drifts towards yellow as it heats up is a bad sign.
- The lumens must be those of the complete luminaire, not those of the bare diodes.
What to Remember
- CRI greater than 90, otherwise reds lie.
- 5,500 to 6,500 K: the light in which the client will judge the car.
- 750 to 1,000 lm/m², distributed in a grid and not concentrated.
- 0.80 hexagons per m²: the detailing density.
See white hexagonal LED kits — color temperature and CRI are indicated on each configuration.
