The ciek function returns the \alpha-opic or blue light hazard luminous efficacy K for any given spectral power distribution according to CIE S026 sec. 3.4. (\alpha-opic) and CIE TN 002 sec. 2.1. (blue light hazard). Any errors in the data set or in results generated with the Lighting Toolbox are not in the liability of the CIE nor me, see licence.
k = ciek(lam,spec,'reference')
Where:
| Parameter | Description |
k | Is the luminous or blue light hazard efficacy. |
lam | Is a vector containing the spectral wavelengths. |
spec | Is a vector or matrix containing the illuminants spectral radiance distribution. |
And the following reference spectra:
| Reference | Description |
'sc' | retinal ganglion cells, s-cone-opic or cyanopic: s_{sc} |
'mc' | retinal ganglion cells, m-cone-opic or chloropic: s_{mc} |
'lc' | retinal ganglion cells, l-cone-opic or erythropic: s_{lc} |
'rh' | retinal ganglion cells, rhodopic or scotopic: s_{rh} |
'mel' | retinal ganglion cells, melanopic: s_{mel} |
'a-opic' | retinal ganglion cells, s_{sc}, s_{mc}, s_{lc}, s_{rh} and s_{mel} |
'BLH' | Blue Light Hazard |
Examples
Determine the melanopic luminous efficacy K_{\text{mel,v}}^{\text{D65}} of standard illuminant ‘D65’:
lam = 380:780; spec = ciespec(lam,'D65'); k = ciek(lam,spec,'mel')
See also: ciespec
Result:
k = 0.0013
Note: The result K_{\text{mel,v}}^{\text{D65}} is given in \text{W}\,\text{lm}^{-1}, for better visualisation of the significant numbers one can multiply the result by factor 1000 to get \text{mW}\,\text{lm}^{-1} as in CIE S026.
lam = 380:780; spec = ciespec(lam,'D65'); k = ciek(lam,spec,'mel')*1000
Result:
k = 1.3262
Note: Be careful with further calcuations if \text{mW}\,\text{lm}^{-1} is used and not standard SI-Units.
Determine the melanopic luminous efficacy K_{\text{mel,v}}^{\text{D55}} and K_{\text{mel,v}}^{\text{D65}} of standard illuminant ‘D55’ and ‘D65’:
lam = 380:780;
spec = ciespec(lam,{'D55','D65'});
k = ciek(lam,spec,'mel')*1000
See also: ciespec
Result:
k =
1.1989
1.3262
That means:
K_{\text{mel,v}}^{\text{D55}} = 1.1989 \text{~mW}\,\text{lm}^{-1}
K_{\text{mel,v}}^{\text{D65}} = 1.3262 ~\text{mW}\,\text{lm}^{-1}
Determine the \alpha–opic luminous efficacy K_{\text{α,v}}^{\text{D65}} off standard illuminant ‘D65’:
lam = 380:780; spec = ciespec(lam,'D65'); k = ciek(lam,spec,'a-opic')*1000
See also: ciespec
Result:
k =
0.8173 1.4558 1.6289 1.4497 1.3262
That means:
K_{\text{sc,v}}^{\text{D65}} = 0.8173 \text{~mW}\,\text{lm}^{-1}
K_{\text{mc,v}}^{\text{D65}} = 1.4558 ~\text{mW}\,\text{lm}^{-1}
K_{\text{lc,v}}^{\text{D65}} = 1.6289 ~\text{mW}\,\text{lm}^{-1}
K_{\text{rh,v}}^{\text{D65}} = 1.4497 ~\text{mW}\,\text{lm}^{-1}
K_{\text{mel,v}}^{\text{D65}} = 1.3262 ~\text{mW}\,\text{lm}^{-1}
Determine the α-opic luminous efficacy K_{\text{α,v}}^{\text{D55}} and K_{\text{α,v}}^{\text{D65}} off standard illuminants ‘D55’ and ‘D65’:
lam = 380:780;
spec = ciespec(lam,{'D55','D65'});
k = ciek(lam,spec,'a-opic')*1000
See also: ciespec
Result:
k = 0.6853 1.4110 1.6286 1.3374 1.1989 0.8173 1.4558 1.6289 1.4497 1.3262
Blue light hazard efficacy of standard illuminant ‘D65’:
lam = 380:780; spec = ciespec(lam,'D65'); k = ciek(lam,spec,'BLH')
See also: ciespec
Result:
k = 1.4422e-06
References: