I thought I would start my series of posts about the scientific methods we used for the study of the marbles with Ultraviolet Fluorescence Imaging (UVF imaging). Works of art are regularly examined under ultraviolet light because it reveals restorations, retouches, varnishes as well as some colour pigments, which have characteristic fluorescence under UV. (Ultraviolet light is often called ‘black light,’ something you’ll be familiar with if you’ve ever set foot in a night club.)
UVF examination and imaging needs to be done in the dark, so we worked in the small x-ray suite in the conservation lab. There are no windows there, and by closing the door, we had all the darkness we needed to look at the small marble objects (they were taken out of the galleries for the study). However, for the large sculptures (which could not be moved), we had to be in the museum galleries at night! That was a little strange…
Simple UV examination can be done with a hand-held UV lamp, which you shine on the work of art as you look at it closely (wearing protective goggles). UVF imaging necessitates a digital SLR camera equipped with UV filters set up on a tripod. The camera is controlled by a computer and photos are taken when UV light is shone on it (either with large lamps, as in the case of Hercules, or hand-held flash with a UV filter). With the photographs, you then have a record of the fluorescence of the pigments and other surface treatments and their location.
Doing UVF was like travelling back to the 80s: the ultraviolet lights, the neon colours, the bright white, and the music playing from my iPod. We had a blast! As I have had this incredible urge to watch Blade Runner since we looked at Hercules under UV on June 22, I put it on my Netflix list… and the DVD arrived today. Enjoy the post and pictures while I watch Harrison Ford and Sean Young in this 1982 sci-fi movie.