As we near the end of our series of posts for British Science Week Vladimir Vilde, a PhD student at UCL, working with English Heritage and David Thickett, Senior Conservation Scientist at English Heritage describe an innovative, low-cost approach to monitoring the condition of paintings across English Heritage properties.
One of the many roles of English Heritage is the management of more than one thousand paintings housed across numerous historic properties. To ensure their care and suitability for display they require regular examination by paintings conservators and conservation scientists. However, given the large number of works of art in the collection, and their geography, this can be very difficult to perform in great detail. Scientific analysis across the entire collection is not possible in this context as it represents a logistical and financial challenge. Instruments can be expensive, hard to move, or simply not tailored for non-invasive analysis.
English Heritage has teamed up with researchers at UCL’s Material Studies Laboratory and the imaging and sensing company LAVision to investigate the potential of exploiting the technology of consumer products, such as laptops and digital cameras, to monitor change in canvas paintings. Such technologies are readily available to conservators and already in use during routine investigations. Cameras in particular are often used in their simplest function, to capture an image, but various techniques of image processing can be used to enhance the observations resulting from just a few photographs.
Digital image correlation (DIC) is one of these techniques and under investigation through this collaborative research. Using two successive pictures, DIC can measure the displacement on an object, which can be used to highlight defects or cracks in a painted surface. There are a large range of specialist cameras that are available on the market for DIC, but the technology is essentially is based on comparisons between two or more photographs, and therefore any camera can be used. This enables the possibility of measuring on site quite easily with off the shelf, accessible tools, but also offers the opportunity to deploy a larger monitoring system across English Heritage properties, due to the low cost of such a setup. The output results are images overlaid with colours according to the amount of displacement captured between successive photographs, which makes it easy to highlight where defects or damage might be occurring when a painting is periodically photographed.
In particular, this project aims to monitor the impact of conservation treatments known as lining, which are applied to the back of paintings to offer strength and support. Conservators need to understand the long term performance of such lining treatments on paintings that are on open display in historic house environments. Therefore, monitoring the structural health of an artwork, through a network of low-cost cameras, has the potential to provide sufficient information for conservators to take action in a more efficient way, before irreversible damage occurs to a painting.
Picture credits: English Heritage
Find out more about Conservation Science at English Heritage