The Ra value ranges from 1 to 99:
- Low value: colours appear dull, faded or unnatural
- High value: colours are displayed brightly and realistically
- Ra 99: almost perfect colour rendering (comparable to daylight)
Why is colour rendering important?
High colour rendering is especially important in situations where colour plays a major role, such as:
- Shops (products need to look attractive)
- Offices (comfortable and natural light)
- Museums and galleries (accurate colour rendering of art)
- Studios and workshops (precision in colour assessment)
What does this mean in practice?
- Ra 80+ → suitable for general use
- Ra 90+ → high quality, true-to-life colours
- Ra 95+ → professional use
In short: the higher the Ra value, the better and more realistic colours are displayed under the lamp.