Open AccessExperimental study on merits of virtual cleaning of paintings with aged varnish
Author(s) -
Giorgio Trumpy,
Damon M. Conover,
Lionel Simonot,
Mathieu Thoury,
Marcello Picollo,
John K. Delaney
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.033836
Subject(s) - varnish , painting , optics , materials science , surface roughness , surface finish , reflectivity , scattering , coating , art , composite material , visual arts , physics
To assess the accuracy of virtual cleaning of Old Master paintings (i.e. digital removal of discolored varnishes), a physical model was developed and experimentally tested using reflectance imaging spectroscopy on three paintings undergoing conservation treatment. The model predicts the reflectance spectra of the painting without varnish or after application of a new varnish from the reflectances of the painting with the aged varnish, given the absorption of the aged varnish and the scattering terms. The resulting color differences between the painting actually and virtually cleaned can approach the perceivable limit. Residual discrepancies are ascribable to spatial variations in the characteristics of the aged varnish (scattering, optical thickness) and the exposed painting (surface roughness).