Researcher(s)
- Akshata Guruprasad, Art Conservation, University of Delaware
Faculty Mentor(s)
- Roxanne Radpour, Art Conservation & Electrical Engineering, University of Delaware
Abstract
Diffuse reflectance spectroscopy (DRS) functions by measuring the scattering of incident light on a surface. The many variants of this approach are often used in art conservation and technical art history to acquire molecular information about pigments and other materials present on a painted surface. Two of the main variants utilized are fiber-optic reflectance spectroscopy (FORS) and reflectance imaging spectroscopy (RIS). RIS camera systems have been used by conservators and scientists to maximize the amount of DRS data gathered. While RIS has the benefit of mapping the entire surface of a painting, the cost of the camera systems and amount of data produced often make it an unfeasible imaging tool for smaller cultural heritage institutions. Comparatively, FORS is significantly more viable in terms of affordable equipment and data processing.
To address the disparity of data gathered by FORS systems vs. RIS systems, one method is to acquire DRS data from smaller spot sizes, which is the goal of this project. This project is the first step towards the broader objective of adapting low-cost imaging instruments in order to expand their functionality in heritage conservation, specifically in obtaining more data from painted surfaces. To achieve the goal of this project, a fibre optic-based ASD FieldSpec 3 spectrometer was adapted to a standard stereo microscope, allowing for DRS data acquisition in the visible and near infrared range (between 400-2300 nanometers). Various painted samples were magnified and analyzed in order to determine the capabilities and limitations of the FORS-microscopy set-up, such as spot-size and the clarity of data. The end result is a workable model that can be replicated by cultural heritage institutions to acquire DRS data similar to that acquired by RIS camera systems.