IR Reflectography
IRRDescription of IR Reflectography
IR Reflectography is an older imaging method suited for the investigation of works of art. Viewing a painting illuminated by visible light only allows us to see the surface paint layers. But the real secrets of painting and insights into the working methods of the artist are hidden under the surface. The aim of most of the imaging methods is to penetrate the surface layer and let us peek into the inner layers of the artwork.
Very useful and common methods for this purpose are IR Reflectography (IRR) and IR Photography (IRP). Both methods make use of the fact that infrared radiation can penetrate the paint layers and thus reach the underdrawing layer. The image below shows the whole spectrum of electromagnetic radiation where it can be seen that the red-underlined infrared (IR) region reaches from about 700 nm up to 4000 nm. One nanometer (nm) being one billionth of a meter.
G. Bellini, Feast of Gods, Detail
Infrared Reflectography Image
Electromagnetic Spectrum
Procedure for IR Reflectography
The illumination source, in this case, is a common incandescent lamp radiating enough infrared rays for this purpose. The reflected IR radiation is then recorded either on infrared film (infrared photography) in a camera equipped with an infrared cutoff filter.
The filter absorbs visible light which would ruin the image on the film and lets the infrared radiation pass. The commercially available IR-films are sensitive to radiation with a wavelength of up to 1100 nm.
The other possibility is recording the reflected IR radiation in a camera with a sensor sensitive to the infrared part of the spectrum. Modern cameras can record IR radiation of wavelengths up to 2400 nm (infrared reflectography).
IR reflectographic research on a painting by Lucas Cranach at Kunsthalle Hamburg with IRR camera Opus Osiris
Video: 'Infrared Reflectography (IRR)' by UCL SEAHA
References
(1) R. van Asperen de Boer, Infrared Reflectography: a Method for the Examination of Paintings, Applied Optics, 7(9):1711-1714, 09/1968. DOI: 10.1364/AO.7.001711.
Instruments
(1) Charles M. Falcoa, High resolution digital camera for infrared reflectography, Review of Scientific Instruments 80, 071301 2009.
(2) Raffaella Fontanaa, Maria Chiara Gambinoa, Marinella Grecoa, Luciano Marrasa, Marzia Materazzi, Enrico Pampalonia, Luca Pezzatia, Pasquale Poggia, New high resolution IR-colour reflectography scanner for painting diagnosis, Istituto Nazionale di Ottica Applicata,Firenze, Italia.
(3) Antonino Cosentino, Panoramic Infrared Reflectography. Technical Recommendations, International Journal of Conservation Science, Volume 5, Issue 1, January-March 2014: 51-60. Available as pdf.
(4) Peccenini, Eva, A scanning device for wide band infrared reflectography. PhD Thesis, Università degli studi di Ferrara, 2012. Available as pdf.
(5) D. Bertani; M. Cetica; P. Poggi; G. Puccioni; E. Buzzegoli; D. Kunzelman; S. Cecchi, A scanning device for infrared reflectography, Studies in Conservation, Volume 35, Issue 3 (01 August 1990), pp
Examples of Use
Catalogue of Paintings Examined by IR Reflectography
J.R.J van Asperen de Boer, J. Dijkstra, R. van Schoute, Catalogue of Paintings Examined by Infrared Reflectography, Nederlands Kunsthistorisch Jaarboek 01/1990; 41(1):59-63. DOI: 10.1163/22145966-90000173
Jan van Eyck, The Ghent Altarpiece, 1430-32
Website of the project “Closer to Van Eyck, Rediscovering the Ghent Altarpiece“. The entire altarpiece was investigated by IR-Reflectography and the complete IRR image can be seen on the website. There are also zoomable high-resolution images and other information on this artwork. Both images are courtesy of this website.
Jan van Eyck, The Ghent Altarpiece, 1430-32, visible light
Jan van Eyck, Portrait of Artist's Wife Margaret, 1439
Groeningmuseum Brugge, Belgium
Jan van Eyck, Portrait of Artist’s wife Margaret, 1439
The painting was thoroughly cleaned and investigated by scientists in the National Gallery in London in 2009. Among other methods, infrared reflectography was employed to gain new insights into the genesis of the painting and into Van Eyck’s working methods.
The infrared reflectograms demonstrated the elaborate and detailed underdrawing of the head and headdress of Margaret while the rest of the figure was sketched in much simpler lines (2).
References
(1) Jill Dunkerton, The Restoration and Technical Examination of Jan Van Eyck’s Margaret, the Artist’s Wife, an online publication of the website ‘Flemish Primitives’.
(2) The restoration of ‘Margaret, the Artist’s Wife’, the website of The National Gallery London.
Lucas Cranach the Elder
Website of Cranach Digital Archive. It contains more than 800 freely accessible high-resolution infrared reflectography images of Cranach’s works with new images being added in the next future.
Infrared reflectography images of 106 of Cranach’s works shown as small thumbnails. Corpus Cranach, the digital archive of the works of Lucas Cranach the Elder and his workshop, University of Heidelberg.
Ingo Sandner, Gunnar Heydenreich, Cranach als Zeichner auf dem Malgrund – Auswertung der Untersuchungen im infraroten Strahlenbereich, Teil 1: Die Jahre um 1500 bis 1512, Cranach Digital Archive. Available as pdf.
Paintings of Hieronymus Bosch in Venice
The website of Bosch Research and Conservation Project shows three paintings by Hieronymus Bosch which are currently located in the Palazzo Grimani in Venice. The three paintings Triptych of St. Uncumber, Hermit Saints Triptych and Four Visions of the Hereafter can be viewed in high resolution with a specially developed viewer. The viewer is interactive and allows viewing the paintings as they appear in visible light and also as infrared photographs and infrared reflectographs. X-ray images will be added in the future.
Hieronymus Bosch, 'The Crowning with Thorns (Christ Mocked)' ca 1490-1500
IRR-Investigation of this painting in the National Gallery in London is described as a case study on the website of the OPUS INSTRUMENTS (1).
For more information on this painting see the page for it on this website.
Hieronymus Bosch, ‘The Crowning with Thorns (Christ Mocked)’ ca 1490-1500
References
(1) Opus Instruments. (2017). Christ Mocked – Opus Instruments.
Camille Pissarro
Pissarro Paintings and Works on Paper at the Art Institute of Chicago
An innovative and interactive catalog of Pissarro’s paintings in the possession of the Art Institute containing a large collection of information including high-resolution and high-quality infrared reflectography images.
Pablo Picasso
Pablo Picasso, Barcelona Rooftops, 1903
Museu Picasso, Barcelona
An interactive feature allowing to change between the normal view and the infrared reflectography image of this painting can be seen on the website of the exhibition Journey through the Blue: La Vie, in the Museu Picasso in Barcelona, Spain.
The investigation revealed a double portrait of a nude couple beneath the painting visible on the surface.
Pablo Picasso, The Woman Ironing, 1904
The Guggenheim Museum, New York
An interactive feature allowing to change between the normal view and the infrared reflectography image of this painting is featured on the website of the New York Times. The investigation revealed a portrait of a man beneath the painting visible on the surface.
Pablo Picasso, The Blue Room, 1901.
Philipps Collection, Washington
The website of The CreatorsProject gives a description of the infrared reflectography investigation of this painting and its results. Underneath the “Blue room” another painting by Picasso, a portrait of a man, was discovered. The website also shows an animation of the transformation from the Blue Room to the Portrait of a Man and several images of the scientists and their investigation.
Further Reading
References
(1) Chad Weiner, Improved Acquisition Technique of Underdrawings in Oil-Paintings Using IR-Reflectography, Thesis, Rochester Institute of Technology, Center for Imaging Science, 1998.
(2) Molly Faries, Techniques and Applications – Analytical Capabilities of Infrared Reflectography: An Art Historian’s Perspective, in Scientific Examination of Art: Modern Techniques in Conservation and Analysis, Sackler NAS Colloquium, 2005. Available as pdf.
(3) Claudia Daffara and Raffaella Fontana, Multispectral Infrared Reflectography to Differentiate Features in Paintings, Microsc. Microanal. 17, 691–695, 2011doi:10.1017/S1431927611000031. Available as pdf.
(4) R. van Asperen de Boer, Infrared Reflectography: a Method for the Examination of Paintings, Applied Optics, 7(9):1711-1714, 09/1968. DOI: 10.1364/AO.7.001711.
(5) John K. Delaney, Jason G. Zeibel, Mathieu Thoury, Roy Littleton, Kathryn M. Morales, et al. “Visible and infrared reflectance imaging spectroscopy of paintings: pigment mapping and improved infrared reflectography“, Proc. SPIE 7391, O3A: Optics for Arts, Architecture, and Archaeology II, 739103 (July 07, 2009); doi:10.1117/12.827493.
(6) Daffara C1, Pampaloni E, Pezzati L, Barucci M, Fontana R., Scanning multispectral IR reflectography SMIRR: an advanced tool for art diagnostics, Acc Chem Res. 2010 Jun 15;43(6):847-56. doi: 10.1021/ar900268t.
(7) J.R.J van Asperen de Boer, J. Dijkstra, R. van Schoute, Catalogue of Paintings Examined by Infrared Reflectography, Nederlands Kunsthistorisch Jaarboek 01/1990; 41(1):59-63. DOI: 10.1163/22145966-90000173
(8) Franz Mairinger, UV-, IR- and X-ray imaging, in Non-Destructive Microanalysis of Cultural Heritage Materials, Comprehensive Analytical Chemistry, Volume 42, 2004, Pages 15–71.
(9) A. Cosentino, Infrared Technical Photography for Art Examination, e-Preservation Science, e-PS, 2016, 13, 1-6. Available as pdf.