Vinci-Editions - Photo shoots

Photo shoots

The engineer Pascal COTTE has invented the first multispectral camera (from ultraviolet to infrared).
On 19 October 2004, he took pictures of the Mona Lisa in the Louvre’s Laboratory of the Museums of France.
The quality of this photo is unique.
For the first time ever, we can admire the original colors (i.e. the colors of the pigments used by Leonardo da Vinci) as well as the infrareds superimposed on the color image.

After X-ray photography, infrared reflectography, X-ray fluorescence, the spectrophotometric approach to color and high-resolution 3D scanning – the first scientific tests undergone by the Mona Lisa for the last fifty years – Pascal Cotte, the founder and scientific adviser of Lumiere Technology, has now added spectrocolorimetric analysis through multispectral photography.

Using the camera he has invented, he spent almost three hours taking pictures of the painting, with light reflected by each pixel, illuminated by a light with a wavelength ranging between 380 nanometers (ultraviolet) and 1,050 nanometers (infrared). The study resulted in thirteen original photos of the masterpiece, with hitherto unequalled accuracy and a resolution of nearly 240 million pixels.

After having calculated the curve of the varnish spectrum, the latter was digitally removed from these images in order to identify the original pigments and virtually restore the portrait without its varnish.

The result reveals the Mona Lisa as Leonardo's contemporaries could admire it at the time : blue, lapis lazuli based sky, pink face, brighter mountains, green trees… But further to the analysis of the shots, which took almost two years, it is possible to go even further. First of all, it has revealed the layers of paint and undercoats covering the wooden panel - poplar – on which it was painted. We can thus make out several restorations, in particular a 2cm wide horizontal strip made of azurite covering the entire width at the top of the painting.

Multispectral shots of the Mona Lisa with a definition of 240 million pixels.
Click on the image to watch the 12-minute video.

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Technological advance

After N. Niepce – the inventor of photography – came Nadar, Talbot and Daguerre, followed by Eastmann and the Lumière brothers. Pascal Cotte has also earned himself a reputation in the history of photography: beyond scientific and artistic progress made with Leonardo da Vinci’s masterpiece, his invention may be a prelude to the era of digitizing works of art. According to him, it might “enable France to become the leader of a digitization and conservation policy of the worldwide pictorial heritage”.
By referring not to what the contemporary eye can see but to the true nature of the pigments used by artists, his invention enables irreproachable shots from an aesthetic and scientific point of view.
The technique carried out by Lumiere Technology also makes it possible to reveal details in the region of a few micrometers and to obtain significant enlargements, thus enabling simulations of varnish removal and restoring works of art, or enhancing the databases of the national archives.

Leonardo’s pigments

If Leonardo was still alive today, he would be spoilt for choice. Over 200 pigments of various origins are available to our contemporary painters. Five hundred years ago, there were only about fourty, Leonardo used less than 20.
Pascal COTTE’s multispectral camera enabled him to identify the pigments which were used to paint the Mona Lisa.
They answer to the names of cinnabar/vermilion (mercuric sulfide), umber, red ochre (also known as ruddle), yellow ochre, verdigris, green earth, lead white, lead-tin yellow, azurite, malachite, Madder lake (also known as alizarin) and buckthorn lake, and the famous lapis lazuli blue (also known as ultramarine).
“The sky is entirely made of this pigment”, explains Pascal Cotte, “except for a 2cm strip which was restored at the top of the painting, which is made of azurite and is easy to spot due to the different or nonexistent network of cracks”.
In order to save the precious pigment (which is slightly transparent), an undercoat often used to be made with azurite.
“This isn’t the case with the Mona Lisa. I took multispectral pictures of paintings dating from that period. If the undercoat is made of azurite, I always find a spot where it shows through, given that the binder becomes more transparent when it ages. My camera is capable of making out 60-micron details. In that case, I would definitely have seen it”.