照明是每单位区域表面上的总发光通量。它以Lux（LX）为单位。
1 fc = 1.1377e-15 ly
1 ly = 878,948,346,339,650.8 fc
例子:
将15 footcandle转换为光明年：
15 fc = 1.7066e-14 ly
| footcandle | 光明年 |
|---|---|
| 0.01 fc | 1.1377e-17 ly |
| 0.1 fc | 1.1377e-16 ly |
| 1 fc | 1.1377e-15 ly |
| 2 fc | 2.2754e-15 ly |
| 3 fc | 3.4132e-15 ly |
| 5 fc | 5.6886e-15 ly |
| 10 fc | 1.1377e-14 ly |
| 20 fc | 2.2754e-14 ly |
| 30 fc | 3.4132e-14 ly |
| 40 fc | 4.5509e-14 ly |
| 50 fc | 5.6886e-14 ly |
| 60 fc | 6.8263e-14 ly |
| 70 fc | 7.9641e-14 ly |
| 80 fc | 9.1018e-14 ly |
| 90 fc | 1.0240e-13 ly |
| 100 fc | 1.1377e-13 ly |
| 250 fc | 2.8443e-13 ly |
| 500 fc | 5.6886e-13 ly |
| 750 fc | 8.5329e-13 ly |
| 1000 fc | 1.1377e-12 ly |
| 10000 fc | 1.1377e-11 ly |
| 100000 fc | 1.1377e-10 ly |
规则