Видима-индуцирана луминесценция на египетска синя: за документирането на ефекта при стенописи in situ и в музеи
Visible-Induced Luminescence of Egyptian Blue: Notes on Imaging of The Effect on Wall Paintings in Situ and in Museums

Summary/Abstract: Egyptian blue is one of the oldest synthetic pigments. It has a particular property – when excited in the visible spectrum to emit strong infra red radiation. The effect is called visible-induced luminescence (VIL). The luminescence of the pigment is so strong, that allows imaging of very small, sometimes almost invisible quantities in the paint. This non-invasive method for identification of the pigment is used in investigation and conservation of cultural properties. The publications on the subject to date are focused mainly on objects in museum collections. The article explores some practical aspects of the imaging of the VIL on wall paintings, both in-situ and in collection or storage. Two case studies are presented: the wall paintings in the late antique tomb in the town of Silistra – examination in situ, and a wall painting fragment from the so-called “Red Church” near the town of Perushtitsa – examination in conservation studio. Different equipment was used as alternative to the one in the publications to date. The results of the examination in the two case studies are compared. The use of different equipment and conditions of imaging are explained and evaluated. The results demonstrate that alternative equipment can be used successfully in VIL of Egyptian blue. The technique can facilitate the examination and documentation of the pigment in conservation of wall paintings and archaeological objects. The method is used for the first time in Bulgaria.

• Details
• Contents