Table 2 Photometric characterization of the lighting interventions.
Lighting system | Standard bedroom lighting | DD-N lighting | ||||
|---|---|---|---|---|---|---|
Ambient light | Reading light | Ambient light | Reading light | |||
Timing | 07:00 h–21:00 h * | 21:00 h–07:00 h * | 06:25 h–07:00 h | 07:00 h–20:00 h | 20:00 h–22:00 h | 22:00 h–06:25 h |
Color properties | ||||||
correlated color temperature | 3513 Kelvin | 3513 Kelvin | 2192 Kelvin | 3588 Kelvin | 2192 Kelvin | 2192 Kelvin |
color rendition (CRI) | 86 | 86 | 82 | 82 | 83 | 82 |
CIE coordinates (x,y) | (0.41, 0.40) | (0.41, 0.40) | (0.51, 0.42) | (0.41, 0.40) | (0.51, 0.42) | (0.51, 0.42) |
Illuminances (mean ± SD; lx) | ||||||
horizontal, at bed level | 140 ± 14 | 52 ± 4 | 20 ± 2 | 209 ± 21 | 100 ± 10 | 20 ± 2 |
vertical, at eye level of patient—20° tilted | 131 ± 15 | 48 ± 5 | 19 ± 2 | 196 ± 23 | 94 ± 11 | 19 ± 2 |
vertical, at eye level of patient—70° tilted | 131 ± 17 | 57 ± 7 | 20 ± 2 | 208 ± 21 | 98 ± 11 | 20 ± 2 |
Luminances (range; cd/m2) | ||||||
at opposite wall | 29–41 | 5–23 | 3–10 | 27–98 | 15–49 | 3–10 |
at ceiling | 21–345 | 5–98 | 2–75 | 25–780 | 13–394 | 2–75 |
α-opic equivalent daylight (D65) illuminance (lx) | ||||||
S-cone-opic | 63.20 | 21.76 | 2.83 | 88.29 | 14.13 | 2.83 |
M-cone-opic | 129.69 | 44.66 | 14.32 | 178.58 | 71.59 | 14.32 |
L-cone-opic | 151.71 | 52.25 | 20.70 | 208.52 | 103.49 | 20.70 |
rhodopic | 92.04 | 31.70 | 7.73 | 129.94 | 38.66 | 7.73 |
melanopic | 77.10 | 26.55 | 5.88 | 112.83 | 29.41 | 5.88 |
