The companies Ingelux, Aelsys and Sklaer have developed programs to monitor the colour temperature on paintings as in Mona Lisa in Le Louvre.
Total control of spectra and luminous power
Two different pilot modes were suggested: the first one dedicated to colorimetric adjustments before the final on-site delivery and the second one for current operations, interfaced with DALI protocol used in the Louvre.
The first aspect was particularly relevant concerning the innovation.
We have designed a colorimetrical tool, in line with the ongoing research of the International Council of Museums (ICOM) and the International Lighting Commission (CIE). This tool allows us to navigate in the colorimetric space, to freely control the chromatic coordinates of emitted light while disposing at any time of a light with an optimal quality (high Colour Rendering Index and maximal Gamut Area). The development of this software has required spectral calibration of each colour channel and correction due to optical systems by using an integrating sphere.
However, the conservation Department of the Louvre Museum had to make final decisions concerning these adjustments; we have elaborated a protocol for on-site adjustments, in front of the panting of Mona Lisa. The final adjustment has been decided by the curator, Vincent Delieuvin, assisted by the architect of the “La Joconde Room” Lorenzo Piqueras, under mixed general lighting conditions (fluorescent light with a little bit of natural light).
It is essential to insist on the innovative process, allowing the curator to adjust the light and colours on a painting and to render the exact colours of the work with high fidelity as well.
INGELUX, Lyon France
|CCT with high CRI||
Adjustable from 2700
until 3800 K
3200K selected for Mona Lisa
|Colour shift from locus||N/A||Adjustable from –0,02 to 0,01|
|CRI||> 90||CRI between 95 and 98 when on locus|
|Colour Quality Scale (CQS)||> 85||
> 95 for Mona Lisa
> 85 maintained for various CCT between 2700 K and 3800 K