Illuminants describe different spectral distribution curves of light sources. In colour measurement, they enable to reconstruct different illumination characteristics.
- Illuminant A: light bulb (2856 K)
- Illuminant DXX: Natural daylight (D = daylight, XX = colour temperature)
- Illuminant D65: Average noon daylight under cloudy sky (6500 K)
- Illuminant C: Artificial daylight simulated by light bulbs with filters
- Illuminant E: No real light source, energetic equivalence point
- Illuminant F: Fluorescent lamp