
“Vision is the art of seeing what is invisible to others,” or so said Jonathan Swift in 1745. If so, then much of the work in the field of heritage science is concerned with the visionary; looking deeper into objects, artworks and monuments of cultural significance. In a recent paper published in Heritage Science, SpringerOpen’s open-access journal for the analysis of objects, materials, artifacts and artworks of cultural and historical significance, a group of researchers used imaging spectroscopy techniques to achieve just that.

Imaging spectroscopy is the “simultaneous acquisition of spatially co-registered images in many spectrally contiguous bands;” in other words, using different bands of light intensity to reveal more about an image than a simple color photograph could. It has many uses, particularly images of the earth or of celestial bodies, but what would we see if we used it to look at fine art?
The researchers, from the National Gallery of Art, used two novel hyperspectral cameras on various works of art, including Pablo Picasso’s The Tragedy, and the results are available in their paper “Visible and infrared imaging spectroscopy of paintings and improved reflectography.”
The Tragedy (1903) is part of Picasso’s “Blue Period,” a set of somber, monochromatic paintings in shades of blue. By using imaging spectroscopy, however, the researchers were able to detect and filter wavelengths of light, revealing not only the underdrawings of the figures in the painting but also drawing and sketches on the canvas that are not part of the finished piece, including a hose and a caricature of a man (see image below).

As well as a fascinating look at the processes behind these masterpieces, imaging spectroscopy has a practical use for works of art as well. The images below show the results from an analysis of a panel painting entitled Maestà (Madonna and Child with Four Angels) by a follower of Duccio di Buoninsegna, from the late 13th century. The false-color image (c) shows us the differences in material: that area of different color under the eyes is most likely an earlier restoration of the panel: vital information for conservators and museum researchers.

The paper is part of Heritage Science’s article collection “Imaging and Analysis of Cultural Heritage Materials,” and, as with all articles in Heritage Science and SpringerOpen, is fully open-access and available online.
For more papers like this and up-to-date research in the field of heritage science, visit the Heritage Science website and sign up for the latest article alerts.