of artistic heritage
Transcription
of artistic heritage
Diagnostics & conservation of artistic heritage Franco Casali Department of Physics, University of Bologna Ravenna – 27 September 2012 1 Medicine has had an impressive improvement by the new diagnostic techniques as Computed Tomography, PET, NMR and so on. The same type of techniques are more and more used also in support to Cultural Heritage assets. My brief presentation will show some applications of electromagnetic radiations (from infrared to X-rays) for helping the conservation and recovery of some masterpieces. Penetration of e.m. radiation into the matter UV SURFACE PAINT PICTORIAL LAYER DRAWING PREPARATION SUPPORT VIS IR XR Infrared reflectography INFRARED REFLECTOGRAPHY Code palimpsest, preserved at the Biblioteca Nazionale Universitaria of Turin (Italy) and severely damaged during the fire that ravaged the library during the nights of 25 and 26 January 1904, destroying much of his collection of manuscripts. By courtesy of PHOTOEVOLUTION INFRARED REFLECTOGRAPHY By courtesy of PHOTOEVOLUTION INFRARED REFLECTOGRAPHY IIt is possible to read both sides of the document! By courtesy of PHOTOEVOLUTION X-Ray Fluorescence (XRF) X-Ray Fluorescence (XRF) The Principle Each of the atomic elements produces a unique set of characteristic x-rays. XRF analyzers measure the spectrum of the characteristic x-rays emitted by the different elements in the sample when it is illuminated by high energy photons (x-rays or gamma rays). Applicazions of XRF XRF is suitable for the analysis of paintings (frescos, paintings on wood or canvas, …) as the Xray penetration is of the same order of magnitude of the thickness of pigments. One can well identify: surface elements deriving from air pollution (sulfur, clorine, calcium...) Elements coming from previous restorations Elements present in the pigment used by the artist Sulfur is very frequent and it comes from the combustion of candles, wood, carbon, oil, gasoline, ... X-Ray Fluorescence Padua: “Scrovegni Chapel”, by Giotto X-Ray Tube Detector MCA By courtesy of G. Buccolieri, A. Castellano, R. Cesareo Applicazions of XRF - Frescos Cesareo, R. , Castellano, A., Buccolieri G., et al. Nuclear Instruments and Methods in Physics Research, Section B: Volume 213, January 2004, Pages 703-706 3D X-Ray Tomography Cone Beam Tomography CT system with EBCCD An intensified camera collects the image produced by the X-rays on a scintillating material screen 30x30 cm2, that represents the radiographic projection of the object. 3D CT of an Egyptian cat shaped coffin X-ray parameters Emax 70 keV I 3 mA Exp 200 ms / view CT parameters Size: 37 x 10 x 20 cm3 Views: 360 Voxel: 600 µm Detector: Ebccd Collaboration: Archaeological Museum - Bologna, Italy Inside the coffin there is a mummy of cat The bones are visible 360 degree radiographs Collaboration: Archaeological Museum - Bologna, Italy 3D virtual opening of the coffin to “extract” the bones 3D CT Collaboration: Archaeological Museum - Bologna, Italy 3D CT at “Opificio delle Pietre Dure” Florence (Italy) CT analysis of the famous panel painting “The Goldfinch Madonna” by Raffaello at “Opificio delle Pietre Dure” (Florence) Width 77.2 cm Height 107 cm CT in collaboration with for “Opificio delle This3Dtable is too large a medical CT! Pietre Dure” in Florence CT analysis of the famous panel painting “The Goldfinch Madonna” by Raffaello First test with a CT of a modern wood table Parameters: Vmax: Size: Voxel: Views: 200 kV 95x120x2 cm3 1.5 mm 360 CT analysis of the famous panel painting “The Goldfinch Madonna” by Raffaello Wood inserts dating back to the first restoration in the XVI century thickness CT analysis of the famous panel painting “The Goldfinch Madonna” by Raffaello 3D CT in collaboration with “Opificio delle Pietre Dure” in Florence CT analysis of the famous panel painting “The Goldfinch Madonna” by Raffaello Before During the restoration After 3D CT in collaboration with “Opificio delle Pietre Dure” in Florence CT of the “Globo Celeste” by Vincenzo Coronelli In the ancient library of Faenza, before the second world war, there were two globes: the celestial (left) and the terrestrial one (right). Vincenzo Coronelli (1650 - 1718) This globe was created by the famous Mapmaker and Cosmographer Vincenzo Coronelli. Scheme of the CT system Experimental set-up The radiographic investigation gives important information, but only the CT analysis makes it possible to reconstruct the entire inner structure and its exact geometry. After bombardment during II world war The restorer (Prof. N. Scianna) found the original maps of the globe so it was decided to reconstruct it Courtesy of Prof. N. Scianna Courtesy of Prof. N. Scianna Courtesy of Prof. N. Scianna Courtesy of Prof. N. Scianna Earth Globe of Globo ‘Danti’ (~1570) Palazzo Vecchio – Florence The Map room (“Sala delle Carte geografiche”) within Palazzo Vecchio, with the ancient large globe created by Egnazio Danti around 1567, on assignment of Cosimo I de’ Medici, duke of Florence. ‘Digital X-Ray Imaging’ Group ‘Digital X-Ray Imaging’ Group Professor : Casali Franco franco.casali@yahoo.it Researchers : Morigi Maria Pia Bettuzzi Matteo Brancaccio Rosa