LIGHT PIPING: A NEW LIGHTING SYSTEM FOR MUSEUM CASES
The advantages of the light piping system are many. First, since the light source is not located inside the case there is no heat build- up that could damage the objects inside. Lack of heat buildup is particularly important for objects made of organic materials and hygroscopic materials that are sensitive to heat and drying out as well as of materials that expand and contract when exposed to fluctuations of heat.
The remote light source also means that maintenance of fixtures does not entail opening or disturbing the case itself. Thus delicate materials inside the cases are not subjected to any unnecessary handling or potential accidents by maintenance staff. The remote light source also assures that the environment in climate-controlled cases is not disturbed by routine light maintenance.
As the focus of each lamp is fixed at the end of the pipes, there is no need to refocus them when bulbs are changed. Thus the integrity of the aesthetic judgments initially made by the lighting designer is preserved.
While the technology utilized in this system is “high tech,” its service requirements are “low tech,” requiring no maintenance or moving parts. At most, it may be necessary to replace the prismatic film after roughly 10 years, the estimated life of the film. This life may be extended considerably by using light sources with little or no ultraviolet component or by filtering out the ultraviolet component before the light enters the pipe.
Finally, the system allows for maximum flexibility and creativity in exhibit case design, layout, and lighting. Field Museum designers have found this piping system to be extremely flexible in creating a wide variety of lighting effects in cases that would otherwise have been extremely difficult to illuminate. By eliminating some of the problems conservators have with conventional lighting systems, light piping illuminators provide conservators as well as designers with a valuable new tool for exhibition conservation. The applications mentioned here are but a start; prismatic film and the light piping system have tremendous potential for exhibition lighting.
I am indebted to Paul Martin, former lighting designer at Field Museum, for providing information about prismatic film in general and our use of it in particular. I am also extremely grateful to Steven G. Saxe, research supervisor at 3M Visual Systems Division, Austin, Texas, for providing information and reading and commenting on various drafts of this paper.