Face to face - close range inspection of head vases
Keywords: Close range, fringe projection, 3D scanning, cultural heritage, head vases
Abstract. Several hundred attic head vases are known worldwide and stored in museums and collections. In 1929, Beazley has categorized twenty groups (A-W) based on stylistic properties and historic methodology. Head vases are assembled in several steps, most important for our comparison is the moulding of the head area. While the other parts of head vases like the size of the handle and the painting can differ significantly from each other, one can notice similarities in the head shapes of the same group. Since molds were used to shape the heads, our initial hypothesis was to perform a quantitative comparison of head shapes based on digital scan data. Comparison of scan data is straight forward and is very similar to quality control and inspection processes in industrial applications. Nonetheless, quality control of approximately 2,500-year-old artefacts that are distributed among several different places is not straight forward. Initial analysis was performed on older scan data. In addition, a high-resolution fringe projection scanner was employed to scan further head vases in additional museums in Germany and Italy. Scan resolution and accuracy of approximately 0.1 mm in all dimensions were required to reveal differences below 1 mm. All new scans were performed with an AICON SmartScan-HE C8. This scanner captures not only shape, but at the same time records color textures which can be employed for presentation or future analyses. Shape analysis results of the head areas do not only confirm that it is likely that the same mold was used for shaping some of the head vases. According to these results, it is also not unlikely that a first generation of larger head vases was used to prepare molds for consecutive generations of head vases that are slightly smaller by 10-15%. This volume loss resembles closely the volume loss observed after oven-burning of pottery. Scanning will continue to increase the data set for further analyses.