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
[email protected]
Researchers :
Morigi Maria Pia
Bettuzzi Matteo
Brancaccio Rosa