Local Workshops, Lectures, Conferences, and Courses
Announcements of DC-area courses, workshops, and lectures can be sent to wcg@washingtonconservationguild.org for posting on this page. Please include “Website item” in the subject line.
National Gallery of Art, West Building Lecture Hall
NON-DESTRUCTIVE AND CONTACTLESS ANALYSIS OF WORKS OF ART
PROF. MADY ELIAS
Head of the group Optics and Art
Institut des Nanosciences de Paris
Université Pierre et Marie Curie
FRIDAY, OCTOBER 23, 2009
11:00 A.M.
NATIONAL GALLERY OF ART
WEST BUILDING LECTURE HALL
This lecture will focus on the imaging of stratified pictorial layers, on the identification of their components and on the recognition of some artistic techniques. The developed processes are non-destructive, contactless, can be carried out inside a museum and provide results in quasi-real time.
Three recent instruments will be presented for these purposes: a confocal microscope (µsurf), optical coherence tomography (OCT) and a multifunctional goniospectrometer (GOSPEL).
- 2D and 3D imaging of stratified varnished objects are obtained by use of confocal microscopy and imaging of stratified pictorial layers by OCT with micrometer resolution in the three dimensions.
- Pigments and dyes of the upper layer are identified by diffuse reflectance spectroscopy recorded with GOSPEL or with a multi-spectral camera. Pigment identification of the under layer is obtained by theoretical modeling and will soon be realized using OCT.
- Varnish identification is deduced from UV- fluorescence recorded with GOSPEL. These provided identifications are highly probable but never sure, because no sampling is used and because they use mathematical comparisons with databases. They have been nevertheless checked many times on known samples and on real paintings by comparison with chemical analysis after sampling.
- Glaze techniques are discriminated from pigment mixtures by use of colorimetry recorded with GOSPEL.
- The three gold application techniques (on mixtion, bole or eggshell) are
recognized with goniophotometry recorded with GOSPEL.
