Machine that can reveal artworks’ secrets from afar

Researchers have designed a new multispectral imaging system which is smaller, more portable and less expensive than what is already available.

It is so effective that the high resolution imaging could be used, for example, to examine the ceiling of Saint Paul’s Cathedral from the ground – without the need for scaffolding.

In galleries, the camera could be set up in the centre of a room and any painting could be examined without moving the instrument.

It could help dealers and auctioneers in identifying original works, dating them, separating the different hands involved in a picture and tracing restoration work carried out on a painting.

As with other larger multispectral devices, the new system captures details invisible to the naked eye. The portable design features a filter wheel mounted to a camera, which is able to capture light from frequencies beyond the visible light range.

This provides information about the paint layers and nature of the pigment used by the artist, and helps identify where overpaint and repair work has been carried out over time.

The Engineering and Physical Sciences Research Council has been funding the project at Nottingham Trent University over the last five years. Senior lecturer in physics at the university Dr Haida Liang said: “The camera is perfect for in-situ examination of paintings.”

The Nottingham Trent team have already used the device to study Botticelli’s Descent of the Holy Ghost (c.1500-1510) at the Birmingham Museum and Art Gallery.

The research revealed areas in the Botticelli which had been over-painted as well as areas of damage and past conservation. They were also able to see through the paint layers to the surface beneath, revealing cracks under the paint. Where the paint above had not cracked, this suggested that the paint was applied later.

By Alex Capon