Following a restoration costing more than $2 million, one of the world’s most famous fresco paintings, found in the Scrovegni chapel in Padua, Italy, is once again open to the public. The masterpiece by Giotto, which was commissioned by the artist’s Paduan patron Enrico Scrovegni, depicts a cycle of 100 biblical scenes and covers the walls and ceilings of the 700-year-old church. The restoration, a team effort led by Giuseppe Basile, director of the Central Institute for Restoration, required 150,000 hours of work.

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To ensure that visitors flocking to the location are certain of seeing the frescoes at their best, the ideal combination of fluorescent and discharge lamps and daylight was found following lengthy tests conducted by a team of experts. The project’s LD, Lorenzo Fellin, says, “When approaching the task of illuminating a work of art of this importance, the first consideration regarded the ‘legitimacy' of using artificial light. There was considerable debate, from a cultural point of view, among the members of the committee for the protection of the chapel: Some said that the chapel originally didn’t have any form of lighting, apart from candles during the liturgical celebrations. They also said that, apart from a certain period each day, which was very limited during the autumn and winter, the frescoes couldn’t be seen with natural daylight.” He adds, however, that certain things—the way sunlight treats Christ’s halo in the Final Judgement section of the frescoes or the way March sunlight illuminates the portion depicting Scrovegni himself offering the chapel to God—indicate that Giotto was aware of natural lighting and its effects on the painting. Still, he says, “Daylight disturbed viewing, rather then helping it.”

With this initial debate over, the members of Fellin’s team faced the challenge of lighting the frescoes in a soft, delicate manner, without inappropriate accents, and, above all, ensuring perfect viewing conditions without risking damage to the painting. Thus a two-year analysis was carried out in collaboration with some of Fellin’s final-year students, with the Galileo Ferraris Instituto Elettrotecnico Nazionale in Turin providing the necessary instruments and a team of experts. “We carried out a chromatic characterization on the frescoes,” says Fellin, “using an MIR (mobile imaging radiometer) system to measure the reflection factors when they were illuminated by different light sources, including daylight. On the basis of these results, we created a combination of types of light able to achieve ideal conditions for viewing these works. The restorers found this approach very interesting and we gave them the same mixture of lighting in advance to carry out restoration work.”

The need for a totally unobtrusive permanent lighting installation was solved with a setup using instruments placed on the floor, on either side of the platform on which visitors walk, located in the center of the chapel and completely out of their sightlines. Special optics were fitted to ensure even coverage of the large wall area--no easy task, as some areas are almost 50' above the fixtures’ positions.

The Disano Group and Osram donated the system’s fixtures and lamps. A series of custom containers was designed to hold the instruments. There is a total of eight metal containers, each equipped with a Disano Evoluzione and Lunar fixture with a 30° beam angle covering different areas of the walls and ceiling and fitted with Osram Lumilux De Luxe fluorescent tubes. The Evoluzione is a sheet-metal asymmetric direct light with a 58W tube, while the Lunar is an injection-molded polycarbonate unit fitted with a pair of 18W tubes. Both are Disano standard products, with modified optics. The tubes’ additional phosphors give a better spectral color distribution and excellent color rendition: 3800K (cool white, to emphasize the blues) and 3000K (warm white) versions were chosen.

At the front of each of the custom containers, which are designed to avoid light spill as well as to make the hardware as unobtrusive as possible, a smaller container houses a Disano Bario. These die-cast aluminum units, each with a 26° beam angle, are used to light the vault with an Osram Powerstar HCI 70W single-ended metal halide lamp (Again, with a 4200K cool white bulb to highlight Giotto’s legendary blue). This lamp was also chosen because it retains its color temperature throughout its life, as the filler substances cannot escape from the gas-tight ceramic discharge tube. Compared with conventional metal halide lamps with quartz discharge tubes, these offer an average of 25% greater luminous efficacy and improved color rendering.

At the top of the walls in the apse, an adjustable bar with four Gi OttO spotlights by Fosnova (a member of the Disano Group) fitted with narrow-beam (8°) Halospot AR111 75W tungsten halogen lamps supplies accent lighting for the altar’s statues. The entire system can be dimmed according to the amount of daylight and there are plans for a sensor to automate this facility.

Osram managing director Paolo Colombo concludes, “In a country like Italy, with over half the world’s art treasures, the quality of life also means preserving these works of art and enabling them to be appreciated. The Scrovegni Chapel is a splendid present-day example of what lighting can do in the service of art, and at Osram we have even closer ties with this project, as we supplied the first discharge lamp-based lighting system back in 1986.”