Ratio of illuminance and uniformity requirements
Ratios between different illuminances and uniformity requirements.

Illuminance, working area |
Illuminance, immediate surrounding area |
Illuminance, peripheral surrounding area in relation to immediate surrounding area |
≥ 750 | 500 | 1/3 |
500 | 300 | 1/3 |
300 | 200 | 1/3 |
200 | 150 | 1/3 |
150 | Working area | 1/3 |
100 | Working area | 1/3 |
≤ 50 | Working area | 1/3 |
Uniformity within the working area depending on the vision task and activity. Uniformity within the immediate surrounding area min/avg at least 0.4. Uniformity within the peripheral surrounding area min/avg at least 0.1.