Image Spectroscopy mapping technique for non-invasive analysis of paintings

Wideband and near-infrared reflectography is a familiar imaging technique for conservators. For many decades it has been the most effective method for providing an extensive knowledge of underdrawings, retouchings, and pentimenti. In this study, a narrowband and multiwavelength imaging (image spectroscopy) system assembled around a lead oxide-lead sulfide (PbO-PbS) vidicon camera is described and applied to the investigation of paintings in the visible and near-infrared regions. A suitable methodology has been set up in order to make the measurements accurate and reliable. The technique has been applied to the detection of different pigments in the 16th-century panel painting The massacre of the ten thousand martyrs by Jacopo Pontormo. .