Characterizing the Immaterial. Noninvasive Imaging and Analysis of Stephen Benton's Hologram Engine no. 9

Invented in 1962, holography is a unique merging of art and technology. It persisted at the scientific cutting edge through the 1990s, when digital imaging emerged and supplanted film. Today, holography is experiencing new interest as analog holograms enter major museum collections as bona fide works of art. In this essay, we articulate our initial steps at Northwestern's Center for Scientific Studies in the Arts to describe the technological challenges on the conservation of holograms, emphasizing their nature as an active material. A holographic image requires user interaction to be viewed, and the materials are delicate and prone to deterioration. Specifically, we outline our methods for creating digital preservation copies of holographic artworks by documenting the wavefront of propagating light. In so doing, we demonstrate why it remains challenging to faithfully capture their high spatial resolution, the full parallax, and deep depths of field without terabytes of data. In addition, we use noninvasive analytical techniques such as spectral imaging, X-ray fluorescence, and optical coherence tomography, to provide insights on hologram material properties. Through these studies we hope to address current concerns about the long term preservation of holograms while translating this artform into a digital format to entice new audiences.