Infrared reflectography using 3D laser scanning

A 3D laser scanning instrument, equipped with an optical transmitter containing a continuous 785 nm diode laser, was used in order to obtain infrared reflectography data of oil paintings. The investigation was carried out in two modern oil and acrylic paintings on canvas and a late 16th century panel painting. In the first case results were compared with existing documentation of the artistic process and in the second with a previously elaborated study by IR reflectography. Data recording took as short as five minutes, providing an IR image comparable to those obtained by reflectography in the IR-A zone of the spectrum. The technique additionally provides high resolution topographic data of the artworks’ surrounding, such as frame and adjacent walls, and has potential to be developed into an alternative method for investigation of pigment layers on virtually any surface, especially if these are of great dimensions or almost inaccessible.