CIE 191:2010 Recommended System for Mesopic Photometry Based on Visual Performance: 79 pages, ISBN 978 3 901906 88 6, € 146
- Book ID
- 102115952
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 386 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0361-2317
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✦ Synopsis
We recently proposed a 28 photopic luminosity function, V D65 * (k) [J Vis 2005;5:948-968], which improves upon the original CIE 1924 V(k) function and its modifications, while being consistent with a linear combination of the Stockman and Sharpe [Vis Res 2000;40:1711-1737] long-and middle-wavelength-sensitive cone fundamentals [L(k) and M(k), respectively]. Its derivation was based on 25-Hz heterochromatic flicker photometric (HFP) data obtained from 40 observers of known genotype on a 1000 troland white (D65) background. However, as a result of an analysis of new luminous efficiency data obtained on an series of chromatic backgrounds [J Vis 2008;8:1-26], we now recognize that the 25-Hz flickering targets, though near-flicker-threshold, altered the mean chromaticity of the adapting background. Consequently, we have revised the original analysis, taking into account the changes in mean adapting chromaticity with target wavelength. Our reanalysis of the individual and mean data shows that the V D65 * (k) function for a D65 background should be redefined as 1.89L(k) þ M(k) in quantal terms and as 1.98L(k) þ M(k) in energy terms. The change in the L-cone weighting factor represents a change in luminous efficiency across the spectrum of $0.04 log unit.