National Park Service

Cinema is meticulously crafted magic, but museum conservation is the science that preserves the real-world artifacts that inspire it. At the National Parks Museum Conservation Lab, Ray Mansfield employs multispectral imaging to pull back the curtain on history, using wavelengths far beyond the visible spectrum to detect hidden inscriptions and chemical coatings. Three radiation bands define the invisible While we perceive the world in visible light, Mansfield focuses on three distinct bands: visible, ultraviolet (UV), and infrared (IR). Technically, UV and IR are forms of radiation rather than light. By isolating these bands using a standard DSLR camera and a series of specialized filters, conservators can see through layers of leather or detect the chemical signature of tree resins. The process is a technical dance of blocking visible light to allow specific radiation to hit the sensor, turning a simple camera into a forensic tool. Uncovering Eisenhower’s hidden inscriptions One of the most striking applications of this technology occurred during the treatment of a trunk belonging to Dwight D. Eisenhower. Visible light showed a clean surface, but UV imaging revealed a fluorescent, brushed-on tree resin. This discovery fundamentally altered the treatment plan; without this data, conservators might have inadvertently stripped away an original protective coating. Similarly, IR imaging on a leather writing desk surfaced a previously invisible inscription dated "May 30," providing a narrative breadcrumb that would otherwise remain lost to time. The technical rigor of the invisible shot Capturing these images requires a strict protocol. Because the camera cannot focus without visible light, Mansfield must lock the focus and settings in a well-lit environment before introducing filters that render the viewfinder pitch black. The resulting IR images are often processed into high-contrast black and white, a technique that allows faint "ghost" writing to emerge from the background noise. It is a meticulous process, reserved for objects where a secret is suspected, proving that in conservation—as in filmmaking—the most important details are often the ones you have to look for.