Conservation staff at the Hugh Lane Gallery have carried out imaging on this portrait of Hartley Withers by Sarah Cecilia Harrison. Withers was a financial journalist who married Letitia Harrison, Sarah Cecilia Harrison’s mother.
Observing how the surface responds to exposure to different wavelengths of the electromagnetic spectrum allows us to gain an understanding of the materials present, and can provide clues as to how a painting was made and its history since.
Technical Analysis
-
Infrared
Infrared image captured using Apollo IR camera. This image shows the limited underdrawing that Harrison carried out before executing the work. Alterations to the composition can be seen around the chin and shirt collar, as well as around the ear and eye. The signature and date, while very dark viewed in reflected light, are quite clearly visible here in the top left-hand corner.
-
Ultraviolet
A UV fluorescence image was captured with UV lighting and a camera with a UV filter. In certain materials, UV light is absorbed, exciting electrons in the material which then release light in the visible spectrum. The light we see as a result of this fluorescence can help us to understand what is present on the surface of the painting, in particular showing us where there is a varnish layer present, and well as if newer retouching has been carried out.
The dull glow throughout suggests the presence of a varnish layer, and the brighter areas suggest fluorescent materials within the paint layer. The well-defined dark patch on the forehead shows an area of later retouching, with the other dark areas on the face possibly showing areas of abrasion on a varnish layer.
-
Multispectral Imaging
Multispectral imaging equipment analyses the reflectance spectra of the same surface captured responding to a range of different wavelengths.
With the Xpecam, this can be used to generate maps indicating areas with similar reflectance spectra. While this provides only qualitative results, these can potentially suggest areas where a specific pigment has been used, which can be confirmed using technical analysis such as X-Ray Fluorescence or Fourier Transform Infrared. Multispectral imaging can be used in this way as a broad first step to guide where we look with much more localised but much more definitive analytical techniques.
Sarah Cecilia Harrison, 1863-1941, Portrait of Hartley Withers, 1906, oil on canvas
Portrait of Hartley Withers, Infrared (IR) reflectograph
Portrait of Hartley Withers, Ultraviolet (UV) fluorescence
Xpecam ‘Pigment map’, showing areas with specific reflectance spectra that may indicate the presence of Sienna pigments.
Xpecam ‘Pigment map’, showing areas with specific reflectance spectra that may indicate the presence of umber pigments.
Xpecam ‘Pigment map’ using different colours to show areas with similar reflectance spectra and therefore, potentially chemically similar pigments.
Portrait of Hartley Withers, before its treatment in 2023.
