Upgrading Standards and Guidelines for the museum lighting: how to include new research results within an outdated model?

Since more than one decade, at the CNR-IFAC laboratories in Florence is active a research branch fully dedicated to the topics museum lighting, including the study of photo-induced phenomena on light sensitive artworks as well as the design and set-up of new tools and protocols for light monitoring in museum environment. This research activity started in 2001, with the partnership in the EC Project LiDo: A LIght Dosimeter for monitoring cultural heritage: development, testing and transfer to market (2001-2004), aimed at providing innovative light-dosimeters, based on a colorimetric principle to respond to the light exposure of highly photosensitive artworks. The outcome of the Project was marketed under the LightCheck® brand and obtained great attention by the museum community, despite its limited diffusion on the market. Apart from the commercial outcome - a new smart tool for monitoring artworks - the crucial novel contribution of this Project was the exploitation of color change - the main undesired effect on artist materials exposed by light - as working principle to monitoring light effects in museum environments and to prevent light-damages. This was the beginning of a new generation of smart sensors for the museum environment, intended to complement the more conventional approach based on data-loggers. Along with research on new prototypes of light dosimeters, the CNR-IFAC research group proposed and developed protocols and procedures for monitoring on time light-induced colour changes in museums objects by means of non-invasive methodologies based on reflectance spectroscopy, such as Fiber Optics Reflectance Spectroscopy (FORS) and Reflectance Hyperspectral Imaging in the Visible (VIS) and Near Infrared (NIR) spectral range. Considering that the colour variation is one of the main undesired effect of light overexposure of artworks, new procedures of colour measurements are crucial for investigations and controls of photo-induced phenomena on artworks on display. Subsequently, the experience gained by the group in the field of risk-assessment of photo-degradation phenomena could be implemented with the participation to the CEN (European Committee for Standardization) TC346/WG6 Working Group Conservation of cultural property: Exhibition lighting of cultural property. At present, the authors are continuing this activity in the framework of the Italian Standardization Body (UNI), participating to the Indoor Lighting of Cultural Heritage Working Group, with the aim of drafting an updated version of the Italian Standard for lighting in museums. During this multi-year work on topics of measuring and controlling lighting effects on artworks, the authors encountered several contradictory aspects linked to the need of conciliating still widely accepted, yet outdated, lighting standards and recommended limits with the new concepts of light monitoring and the new generation illumination technologies. Transferring the new research results to acceptable standards and recommended practices for museums is not an easy task, and many questions remain open. For example: which is the best way to include the most relevant and recent research outcomes (light dosimeters, passive sensors, smart tools, fadometers, etc.) in an updated version guidelines for museum lighting? How the knowledge gained in experimentation on light sensitive materials can be transferred to routine in museums and recommended practices? How the widely-accepted lighting limits have to be upgraded, taking into account the new light sources (LED) introduced in the meantime? Is the color change the most indicated parameter to assess the light damage in photosensitive materials? etc. etc. The present contribution is not intended to present new results in the field, but is rather aimed at discussing the still open problems and sharing the possible solutions related to the challenging task of upgrading the guidelines for museum lighting within the widely accepted framework.