Infrared Reflectography: More Noninvasive Techniques in Art Conservation
What is Infrared Reflectography (IRR) and How Does It Work?
Infrared Reflectography (IRR) is a noninvasive technique used in the art conservation field. One of its prime implementations is to identify the bottom layers of a painting, which allows scientists to observe and identify any preliminary sketches made on the material surface, among other layers (AIC). The longer wavelengths of infrared radiation and thinner paint layers allows infrared reflectography to reveal those layers beneath the surface top (Duffy). This is especially important when examining paintings because it can reveal important information regarding the initial drawings and paint guides created by the artist that are not visible to the naked eye. This is especially important when examining paintings because it can reveal important information regarding the initial drawings and paint guides created by the artist that are not visible to the naked eye, such as the Tibetan Thanka painting depicted in Fig 1. Scientists studied these Thanka paintings in order to document the sketches on the ground layer made by artists for their apprentices to follow. With knowledge of these plans, conservators and art historians can compare such results to the final product, and learn more about the painting process specific to a particular piece.
IRR: Vidicon
Infrared vidicon is the most common device used for infrared reflectolography. This technique was developed in the 1960s by Dutch physicist RJ van Asperen de Boer with hopes of improving the results of infrared photography. Vidicons are portable, and therefore rarely stay inside conservation labs – they are usually on-site at museums, private collections, and other places where art is located. The vidicon is housed inside a high-resolution television camera, along with a television monitor that displays the infrared image, called a reflectogram. It is through this monitor that the reflectogram can be viewed, documented by scientists, and sent to a computer for further research (Faries).
Infrared Photography and Other Resources
Cosentino’s article briefly mentions vidicons and InGaAs cameras being used in addition to infrared reflectolography. He notes that infrared photography is a general term that indicates that a particular art examination is being performed with digital cameras. The use of IR imaging encompasses more than just art historical and conservational terms – it can be used for archeology and other fields regarding cultural preservation.
IR image of Tibetan Thanka, from the Boston Museum of Fine Art
Bibliography
Cosentino, Antonino. “Infrared Technical Photography for Art Examination” e-Preservation Science. Morana RTD, 2016. 1-6. Print.
Faries, Molly. “Analytical Capabilities of Infrared Reflectography: An Art Historian’s Perspective.” Scientific Examination of Art: Modern Techniques in Conservation and Analysis. (March 2003.): n. pag. Web.
Duffy, Kate I. “An Investigation of Palette and Color Notations Used to Create A Set of Tibetan Thangkas.” Historical Painting Techniques, Materials, and Studio Practice. The J. Paul Getty Trust, 1995. 78-84. Print.
“Infrared Reflectography.” The Art Institute of Chicago. The Art Institute of Chicago, n.d. Web. 13 Nov. 2016.
Maev, GR, D. Gavrilov, A. Maeva, and I. Vodyanoy. “MODERN NON-DESTRUCTIVE PHYSICAL METHODS FOR PAINTINGS TESTING AND EVALUATION.” 9th Int. Conference on NDT of Art 2008 Jerusalem, Israel, May 2008 (n.d.): n. pag. Web.
