Laser diode-based projection lighting strategy with peak wavelengths optimization for artwork conservation

A laser diode-based projection illumination system with three primaries was considered with a large color gamut for artwork lighting. This work intends to study the impacts of the peak wavelengths on the light absorption for artworks and then optimize the peak wavelengths to minimize the light absorption for artwork conservation. By varying the peak wavelengths of the three laser diodes, correlations among the incident power, the absorbed power, and the color sample coverage ratio are modeled and studied; to find a trade-off peak wavelength combination for general artwork lighting. Next, a peak wavelength optimization approach is proposed for obtaining minimum light absorbed power based on valuable specific artwork's reflectances. The results show that by our found peak wavelength combination for general artwork lighting, the absorbed power decreases by 5.9% for illuminating the artwork S, respectively, compared to the peak wavelengths recommended by Rec. 2020. In addition, the absorbed radiant flux of 0.48 W is much lower than the absorbed radiant flux under D50 (0.60 W). More importantly, the incident radiant flux under our optimized peak wavelengths decreased from 0.67 W to 0.48 W (decreased by 28.4%), and the absorbed radiant flux decreased from 0.48 W to 0.35 W (decreased by 27.1%) compared to that under general artwork lighting. Therefore, our proposed general artwork protective lighting strategy and peak wavelength optimization strategy efficiently minimize the artwork's absorbed power. (c) 2023 Consiglio Nazionale delle Ricerche (CNR). Published by Elsevier Masson SAS. All rights reserved.