Highly modern LED lighting in the Sistine Chapel


Copyright Governatorato dello Stato della Città del Vaticano - Direzione dei Musei

Highly modern LED light will be illuminating the world famous Sistine Chapel in Rome from November 2014. The Chapel will be presenting its treasures to 4.5 million visitors yearly in a completely new colour diversity, because until now the colours of the famous frescoes by the Italian artist Michelangelo were difficult to recognise in the transition area between daytime and night vision.

OSRAM experts developed the LED lighting concept as part of a project subsidised by the European Union and together with various project partners, including conservators and experts for colour quality and sustainability. The LED lighting concept increases luminous intensity by five to ten times, renders colours more close to reality and illuminates fresco areas with a high level of homogeneity that previously were hardly noticed by visitors.

lighting schematic
The new LED light system consists of three separate installations:
1. Gallery lighting illuminating the frescoes on the walls and ceiling.
2. Gala lighting used as supplementary lighting with conclaves and events.
3. Lighting on "The Last Judgment" fresco.

The project
Implementing a new light system in the Sistine Chapel was one of the most sophisticated tasks in the world of lighting. The specification for completely glare-free illumination, the strict conservational requirements, the immense historical importance of the Chapel itself and the globally unique works of art all demand the necessity for a lighting solution characterised by extremely individual and qualitative technology.

The aims

  • Maximum possible conservational protection of all artworks in the Chapel
  • A significant increase in lighting intensity and uniform illumination without glare for visitors
  • A significant improvement in colour rendering of the frescoes
  • Significant energy savings

Colour metric experts initially analysed the colour pigmentation of the frescoes without physical contact at 280 points on the Renaissance paintings to determine the reflected light spectrum. The results served as the standard for the spectral fine adjustment of the LED luminaires to optimally illuminate the famous works of art in their correct colour palette. The distinctive technical feature: The custom made LED luminaires are capable of controlling the four colour channels of red, green, blue and warm white to enable the frescoes to be presented to visitors just as Michelangelo saw them 500 years ago. Experts from the Vatican and OSRAM specified a colour temperature of 3,500 Kelvin in the Sistine Chapel. Such advanced fine tuning is currently only possible with LED technology.

The special LED luminaires were installed at a height of around ten metres on a narrow ledge in the interior of the Chapel, and are concealed from view for visitors while giving the impression that their light comes in the form of daylight via the windows. The project team was also able to avoid all forms of glare to 100% with the new installation.

The specifically constructed LED luminaire can be individually calibrated according to the colour spectrum to be illuminated via four separately controllable colour channels.

20 LED luminaires on each longitudinal side of the Chapel were installed for visitor lighting purposes in "groups of four" on the ledge. The luminaires contain a total of 140 red, green, blue and white high performance light emitting diodes. The intelligent configuration of reflectors ensures highly uniform and glare-free illumination. The original design of the luminaires was made more slender, enabling them to fit on the narrow ledge. Each of the luminaires has an approximate width of 80 centimetres, and with the heat sink a depth of around 100 millimetres.

LED spots were also installed. These replaced the obsolete gala lighting used with fairs, concerts and of course for the conclave. 30 LED spotlights with 50 watts each were mounted in groups of three between the windows. When required these are motor-driven onto the ledge from their concealment.

The result
With a colour temperature of 3,500 Kelvin, a lighting intensity of 50 to 100 lux and a CRI > 95 colour rendering index, the paintings of the Sistine Chapel are now illuminated with individually adapted and highly efficient LED light. Brightness is also completely dimmable. The immense colour diversity and 3D effects in the famous art of Michelangelo can now be seen for the first time in all their glory by visitors. The historic frescoes are more optimally protected than ever before, because LED light causes significantly less damage than all currently known light sources.

Despite significantly higher lighting intensities and best possible quality of light, energy consumption is reduced (and therefore CO2 commissions as well) by at least 90%. The connected electrical load of the Chapel is therefore also reduced if gala and visitor lighting is included from more than 66 kilowatts to less than 6 kilowatts Full article can be found here: http://www.osram.co.uk/osram_uk/news-and-knowledge/led-lighting-in-the-sistine-chapel/index.jsp