"Comparison of three-dimensional optical coherence tomography and high resolution photography for art conservation studies"Desmond C. Adler, Jens Stenger, Iwona Gorczynska, Henry Lie, Teri Hensick, Ron Spronk, Stephan Wolohojian, Narayan Khandekar, James Y. Jiang, Scott Barry, Alex E. Cable, Robert Huber, and James G. Fujimoto
Optics Express 15, 15972 (2007)
Gold punchwork and underdrawing in Renaissance panel paintings are analyzed using both three-dimensional swept source / Fourier domain optical coherence tomography (3D-OCT) and high resolution digital photography. 3D-OCT can generate en face images with micrometer-scale resolutions at arbitrary sectioning depths, rejecting out-of-plane light by coherence gating. Therefore 3D-OCT is well suited for analyzing artwork where a surface layer obscures details of interest. 3D-OCT also enables cross-sectional imaging and quantitative measurement of 3D features such as punch depth, which is beneficial for analyzing the tools and techniques used to create works of art. High volumetric imaging speeds are enabled by the use of a Fourier domain mode locked (FDML) laser as the 3D-OCT light source. High resolution infrared (IR) digital photography is shown to be particularly useful for the analysis of underdrawing, where the materials used for the underdrawing and paint layers have significantly different IR absrption properties. In general, 3D-OCT provides a more flexible and comprehensive analysis of artwork than high resolution photography, but also requires more complex instrumentation and data analysis.
BMO authors (in alphabetic order):
Fourier Domain Mode Locking (FDML): Spectral mode locking in optics and applications
Optical Coherent Ranging and Optical Coherence Tomography (OCT): Imaging and profilometry with rapidly frequency swept laser sources