Research Jeroen Kalkman on Vermeer's Girl with a Pearl Earing in TU Delft stories
In 2018, Johannes Vermeer’s world-famous Girl with a Pearl Earring underwent a total ‘body scan’: using state-of-the-art techniques, the painting was studied in painstaking detail from top to bottom. It provided a wealth of new insights about the painting and the painter. Four TU Delft faculties worked on the project.
The most recent scientific article explores the use of optical coherency tomography (OCT), an imaging technique similar to ultrasound, but using light rather than soundwaves. OCT is used by ophthalmologists to view the retina in detail. “OCT enables you to show thin layers in detail to a thickness of several millimetres,” explains Jeroen Kalkman, researcher in the Imaging Physics department. “That means we can also look beneath the surface of the painting and see exactly how thick certain layers of paint and glaze are.”
This was not yet possible the last time the Girl was examined in detail during restoration work in 1994. “OCT was still in the early stages of development then,” explains Kalkman. “So, it became a journey of discovery; we had no idea how well it would work or what the result would be.” Although OCT produces high-resolution images, it also has its limitations. Firstly, the size of the surface you can study: this is determined by the lens used and is therefore no larger than approximately one square centimetre. This is large enough for a retina or fingerprint, but not for whole painting. Secondly, the technique is sensitive to vibration, which prevented work from taking place in a museum full of visitors.
The whole story can be read here.