After unlocking the secrets of the Mona Lisa, a French scientist has turned his all-seeing "multispectral" camera on a lesser-known Leonardo da Vinci muse in Poland: the "Lady with an Ermine."

 

Engineer and inventor Pascal Cotte virtually strips away centuries of sometimes sloppy restoration work to provide a digital image of a painting as it may have left the artist's studio -  an abiding question among art historians and art lovers about such masterpieces.

 

Cotte was called in by the Czartoryski Museum in Krakow in southern Poland, which is home to a collection built up over the centuries by the eponymous Polish princely family. His unique 240-megapixel camera uncovers the true colours of a painting, literally: Cotte found that the late 15th Century wood-panel portrait was not painted on the black background visible today."The background was deep blue, very lightly shaded with earth, and probably an azurite mixed with earth," Cotte told AFP. "It's far more beautiful than we thought," said French art historian Jacques Franck, a da Vinci expert who worked alongside Cotte. "Here we have a Leonardo da Vinci which has been masked by bad restoration work and which as a result has perhaps been seen as less important than it really is," Franck said.

 

The "Lady with an Ermine," bought by the Czartoryski family in Italy in 1798, was among the works looted by the invading Germans in 1939. It was hung in the office of the Nazi governor Hans Frank, who then decamped with the portrait when the Germans fled in January 1945. The painting was discovered by U.S. troops at Frank's villa in Bavaria and later returned to Poland.

 

Though a major piece in the Czartoryski collection, nagging doubts persisted over how much of "Lady with an Ermine" was da Vinci's own hand and how much was that of his assistants. Cotte's conclusion, based on a virtual version he built as close as possible to the original, suggests it is nearly 100 percent da Vinci's handiwork. "We haven't learned anything new that will fundamentally alter our understanding of this work," said Anna Grochowska-Angelus, the Czartoryski Museum's chief restorer. But Cotte's scan confirmed the existence of fingerprints which had fuelled Polish experts' long-held belief that the majority of the work was da Vinci's, she said.

 

Cotte, who aims to help historians build up a global archive of digital "originals," has already gazed behind the layers of around 500 paintings, including works by Brueghel, Rembrandt and Van Gogh. He recently took part in an international study of what is arguably the world's most famous painting, da Vinci's Mona Lisa, which hangs in the Louvre museum in Paris. He revealed that her trademark enigmatic smile was originally wider, and that he also had eyelashes, eyebrows and a blanket on her knees.

 

Cotte's camera gives insight into colours, pigments and brush-strokes underneath a weathered surface. "It enables us to break down the light spectrum three levels into the pictorial layer, from the ultraviolet to the infrared, and from the visible to the invisible," he explained. "Multispectral photography provides us with knowledge of the stratification of the successive layers painted by Leonardo and restorers, which enables historical understanding of the way the work was constructed and of subsequent actions," he said. In the "Lady with an Ermine," he discovered hidden traces under the ermine's left paw and muzzle. Franck and Cotte believe da Vinci may originally have painted the ferret-like animal lower down the portrait of the woman thought to be Cecilia Gallerani, who was the mistress of the Duke Lodovico Sforza of Milan. Experts suggest that the ermine, an apparent allusion to the duke, was originally painted in a livelier pose but later altered to appear calmer and thus more noble.