frudawski

# ciek

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:

And the following reference spectra:

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')

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


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 \alphaopic 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

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

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')

k = 1.4422e-06
CIE S 026/E:2018: CIE System for Metrology of Optical Radiation for ipRGC-Influenced Responses to Light. Commission International de l’Éclairage (CIE), Vienna Austria, 2018, (DOI: 10.25039/S026.2018).
CIE TN 002:2014: Relating Photochemical and Photobiological Quantities to Photometric Quantities. Commission International de l’Éclairage (CIE), Vienna Austria, 2014.