3-D Digital Microscopy and Cultural Heritage: A Successful Marriage

The need for observing the microscopic details on artwork surface often occurs during the course of the same restoration work. Standard optical systems such as eyepieces, videomicroscopes or stereomicroscopes represent powerful aids for the restorer during the examination of the preservation status, the decision of the treatment to be applied and interpretation of the peculiarity of the decoration process. In recent years there has been an increasing use of digital videomicroscopes due to their low cost and high convenience, but where the observation of the depth is an important element in the assessment, they cannot fully replace the stereomicroscope. The "feeling" of three-dimensionality provided by the latter can allow to decode textural aspects of interest, but in turn is limited if quantitative data on the depth of the surface is needed. In this case, a versatile solution is represented by the 3D digital microscopes. Since 2007 we are directly involved in the development of devices for 3D reconstruction of surfaces, and now we improve, promote and accelerate the technology transfer to increase the access to this technology. Here, after an introduction on the main features of the 3D digital microscopes we have developed, a review of several case studies are presented. These are representative of microrelief problems which can arise in practice in cultural heritage domain. In particular we report the micromorphological studies of the punchworks on Medieval painting, the granulation motives decorating jewels, the minting toolmarks on Roman coins, the test of laser cleaning on marble artifacts