Light for the Sistine Chapel

The frescoes on the walls and ceiling of the Chapel can now be admired in all their splendour, as a result of numerous and exemplary restorations, but in particular thanks to the work carried out by Osram and Carrier in recent years to improve the conditions of light and air.

A gift for the 450th anniversary of the death of Michelangelo: this seems to be the new apparel chosen by the Sistine Chapel for the world. No one ever saw it like this.

After nearly 600 years, the works of such supreme masters of Italian painting as Pietro Perugino, Sandro Botticelli, Domenico Ghirlandaio, Cosimo Rosselli and Luca Signorelli, who worked in this space together with Michelangelo, have been given a new light and breadth.

Cappella Sistina — **Top**: Sistine Chapel, detail view of the vault by Michelangelo. Photo © Governatorato dello Stato della Città del Vaticano. **Above**: the Sistine Chapel before (left) and after the intervention. Photo © Governatorato dello Stato della Città del Vaticano (left) and Photo Boutique Creativa. © Governatorato SCV – Direzione dei Musei (right)

From now on, the public can admire the frescoes on the walls and ceiling of the Chapel in all their splendour. They seem almost to be endowed with a light of their own, a sharpness of colour and detail that reaches our eyes with surprising freshness and quality; a sight attained in the course of time as a result of numerous and exemplary restorations, the latest – and most important – of which was done 20 years ago, but in particular thanks to the work carried out in recent years to improve the conditions of light and air.

Pietro Perugino, *La Consegna delle chiavi* Sistine Chapel. Before and after the intervention. Photo © Governatorato dello Stato della Città del Vaticano (above) and Photo Boutique Creativa. © Governatorato SCV – Direzione dei Musei (below)

In a concentrated scientific and cultural effort, three years of studies and projects were devoted to the new lighting and conditioning of the Sistine Chapel, with particular regard to the frescoes, from which we can now all benefit. Two strategic choices of protection and conservation, above all of the environment, have, thanks to Osram for the new lighting, to Carrier for the new conditioning, and to an excellent advisory team, created and concluded a cycle of restoration. By now successfully preventive, it projects into the future the aesthetic, scientific and cultural standard attained.

A new “mesopic” light, at once total and precise, gentle and unobtrusive, has restored to the Sistine Chapel a fresh entirety

What light for the world’s chapel?

Antonio Paolucci, director of the Vatican Museums, in presenting the new lighting of the Sistine Chapel to the public for the first time, on October 30th, defined this new light as “mesopic”. At once total and precise, gentle and unobtrusive, it has restored to the Sistine Chapel a fresh entirety. Above all, it has unified the vault, the Last Judgement, and the 15th century frescoes on the side walls.

“A gentle but total illumination was required,” explains Paolucci, “that would be non-invasive, respectful of the complex iconographic, stylistic and historical reality of the Chapel, and capable of rendering a calm, objective and at once delicate appreciation, of recounting in every detail and enabling us to comprehend the whole of that vast depicted catechism which three Popes (Sextus IV, Julius II and Paul III) commissioned to embellish the walls and ceiling of what has always been universally regarded as the world’s chapel”.

7000 LEDs and two new lamps designed, made and offered by Osram have achieved this rather more than extraordinary effect: a controlled light with no dazzle, realised by the wishes of historians and at the service of art.

The project was financed by the European Commission through LED4Art and Illuminate, with two pilot projects at a cost of over 2 million euros in collaboration with Osram (Germany and Italy), the University of Pannonia (Pannon Egyetem, Hungary), Fabertechnica (Italy), the Institut de Recerca en Energia de Catalunya (IREC, Sain), the Vatican City, and other partners in a joint consortium of companies.

The study period of nearly three years included colourimetry experts to examine the pigmentation of the frescoes, determining a reference lighting spectrum, for the precision adjustment of the LEDs to be designed in order to illuminate the colours of the frescoes in the best possible way. A monitoring of prefiguration and simulation was conducted thanks to the high levels of lighting design achieved in Italy too, where part of the work was done by a group of lighting designers, coordinated by Professor Marco Frascarolo of the “Roma tre” University in Rome for FABERtechnica.

One of the most important technical features is the fact that the LED fittings, custom-made under the supervision of Carlo M. Bogani, executive director of Progetto Osram Italia, can regulate the four colour channels – red, green, blue and warm white – to present the frescoes to visitors in the manner closest to how Michelangelo conceived them 500 years ago.

The Sistine Chapel enlightened by Osram with the new detection sensor: temperature (C°) and relative humidity (%). Photo Ufficio del Conservatore. © Governatorato SCV – Direzione dei Musei

Two lighting fixtures to establish two lighting scenes: a museum one and a gala one. The museum lighting scenario, created for public appreciation of the chapel, presents a sophisticated arrangement of reflectors which makes them invisible to the visitor’s eye and guarantees a uniform lighting without dazzle, dedicated to every part of this space, walls and ceiling. To adapt the fittings to the narrow stringcourse, their structure had to be particularly thin and carefully modelled. Each fitting is 80 cm wide and, with its particular heat dissipator, about 10 cm deep. The gala scenario, suitable for more institutional and religious occasions, such as a conclave, sees the installation of 30 LED fitments in groups of three, each with a 50 Watt power. Through a motorized mechanism, they each rotate from their concealed rest position in the stringcourse to the position of direct lighting of a part of the chapel.

The LED fittings can regulate the four colour channels – red, green, blue and warm white – to present the frescoes to visitors in the manner closest to how Michelangelo conceived them 500 years ago

The final result is a brightness of between 50 and 100 lux, ten times more than previously. This can be regulated and ensures the maximum discernment of details of the frescoes, but causes minimal intrusion and hence the least possible ageing. Energy consumption, and hence CO2 emission, have been reduced by over 90%. Also, by combining the Gala illumination with that required or visitors, the necessary volume of electricity drops from over 66 kilowatt to less than 6.

An integral part of the project completed for the new lighting is that of the more technical and functional conditioning system. Developed by Carrier, this is of great importance in ensuring the future use of the Chapel by large numbers of visitors.

The “anthropic pressure” to which the Sistine Chapel is subjected (6 million visitors a year, with occasional peaks of over 20,000 a day) entailed a radical operation to gurantee changes of air, dust and pollution abatement, temperature and humidity control, and carbon dioxide at acceptable levels. This intervention eliminates the risk of a mixture of humidity, pollutants and carbon dioxide which could, in the long term, have jeopardised the correct conservation of the frescoes.

The new Carrier conditioning system uses specially designed software and components. Likewise, it relies on patented energy saving technologies that allow optimal conditioning to be maintained for the protecton of the paintings in the Chapel. A system of intelligent monitoring, linked to video applications by UTC Building & Industrial Systems, enables the HVAC system to read and anticipate visitor numbers and to regulate performance accordingly.

The new system doubles the efficiency and triples the capacity of the previous one, installed by the same supplier, Carrier, in the early 1990s.

Thus the 2,500 sqm chapel and the most important artistic anthology of the Italian Renaissance, where technology and culture have always merged and integrated, offers a new, ideal knowledge, accessible from now on to everybody.

Light for the Sistine Chapel

The frescoes on the walls and ceiling of the Chapel can now be admired in all their splendour, as a result of numerous and exemplary restorations, but in particular thanks to the work carried out by Osram and Carrier in recent years to improve the conditions of light and air.

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