Multi-Spectral Imaging for Archeology

Abstract

Until recently multi-spectral imaging in the field of archaeology has been vastly under-utilized due to the great expense of using specialized films and cameras. A great deal of data remains hidden when observing artefacts such as papyri and pottery shards (ostraca) solely under visible light (400-700nm). The writings on these artefacts are often faded and illegible resulting in much of the information they store being lost. Our approach has been to use modified commercial cameras along with a Coastal Optics 60mm multi-spectra lens to enhance the contrast of the text through the use of Ultraviolet (300-390nm) and Infrared (700-1000nm) Reflectography and computer postprocessing of the RAW images. The results are stunning. A great deal of the text on these artefacts can been made legible and subsequently studied. The underlying principle comes from the fact that pigments and minerals reacting differently to the specific bandwidths of UV and IR light, thereby producing an enhanced contrast version of the once illegible artefact. This information can be later recorded and used to further the understanding of the object itself and the civilization of which it originated. In addition, this photographic technique can be further adapted to study non-textual artefacts such as paintings. These results are consistently obtained, readily reproduced and can be adapted to study all text upon papyri, ostraca and other cultural artefacts. Moreover, the system can be easily moved onsite to museums and galleries