The change of sunlight intensity of indoor windowsill with time.
| Time intervals of irradiation per min | 0–10 | 10–20 | 20–30 | 30–40 | 40–50 |
| Light intensity ranges per Lux | 6515–13 280 | 10 270–26 550 | 24 260–7744 | 31 010–55 170 | 10 350–1546 |
| Time intervals of irradiation per min | 0–10 | 10–20 | 20–30 | 30–40 | 40–50 |
| Light intensity ranges per Lux | 6515–13 280 | 10 270–26 550 | 24 260–7744 | 31 010–55 170 | 10 350–1546 |