frudawski

# cief1

The cief1 functions calculates the f'_1 error of photometers, or more precisely the mismatch index to the V(\lambda) curve. 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.

Note: with CIE 179 the f'_1 error was extended for colorimetric photometers and hence for the CIE \bar{x}, \bar{y}, \bar{z} functions.

Usage:

f1 = cief1(lam,spec,'reference')

Where:

Examples

Determine the f'_1 mismatch index for a given filter function:

% create V(lambda) function
lam = 380:780;
VL = ciespec(lam,'VL');
% change VL function slightly
spec = VL.^(1.05);
% determine f1 error
f1 = cief1(lam,spec)
% plot both functions
plot(lam,[VL;spec])
legend('V(\lambda)','test filter function')
xlim([380 780])

Result:

f1 = 2.4148

Determine the f'_{1,x} mismatch index for a given \bar{x} colour filter function:

% create x-bar function
lam = 380:780;
x = ciespec(lam,'x');
% change x-bar function slightly
spec = x.^(1.05);
% determine f1,x error
f1x = cief1(lam,spec,'x')

f1x = 2.7693
ISO/CIE 19476:2014(E): Characterization of the performance of illuminance meters and luminance meters. Commission International de l’Éclairage (CIE), Vienna Austria, 2014.
CIE 179:2007: Methods for Characterising Tristimulus Colorimeters for Measuring the Colour of Light. Commission International de l’Éclairage (CIE), Vienna Austria, 2007, ISBN: 978 3 901906 60 2.