Infrared light that falls with the 780-3000 nm range (near infrared) of the electromagnetic spectrum can be particularly useful for revealing preliminary sketches, underdrawings, or compositional changes that lie beneath visible paint layers. Areas that have been painted using a significant amount of carbon black readily absorb IR light (appearing black in the IR images) while other pigments, such as vermillion, are transparent. Using an IR camera equipped with an InGaAs detector, a team from Washington and Lee University's Chemistry Department generously devoted their time and equipment in an effort to acquire images of the painting. (Pictured here: Dr. Erich Uffelman, Dr. Anthony Lagalante, Dr. Amanda Norbutus, Sam Florescu, Alex Garcia, Ashley Ooms)<br/><br/><a href="http://www.artcons.udel.edu/about/kress/examination-techniques-and-scientific-terms/infrared-reflectography" target="_blank">More information on Infrared Reflectography can be found here</a>
Abner, the head of King Saul's army, was originally adorned with a helmet possessing a prominent feather plume. The IR reflectogram also reveals that Abner's entire head was positioned much lower during the early painting stages and was shifted upwards.
The IR reflectogram of the upper left corner revealed the pattern of folds in the drapery but more importantly the original shape of the weapon that is held by the standing soldier. Previous restorers misinterpreted the weapon to be a spear; however, the black outlines of a halberd, a combined spear and battle-ax. The IR image helped the conservation team during the retouching phase of the treatment to restore the shape of the original halberd.