The hall of mirrors - Château de Versailles


Commissioned by Louis XIV from his architect, J. Hardouin Mansart, the 73 meter long Château de Versailles Hall of Mirrors, is the link between the War Room and the Peace Room. Charles le Brun’s paintings, which decorate its 1000 square meter, 12-meter high ceiling, evoke the most important events of the reign’s first seventeen years.

This masterpiece, classed as part of the worldwide heritage of humanity, is seen each year by 4 million visitors. In 2002 a decision was made to undertake a complete restoration, which had never been done since the 17th century.
During the day, the hall is lit by 17 windows and 357 mirrors, nighttime festivities are illuminated by candles in the chandeliers and candelabras which shimmer and are reflected in the mirrors.

The Head Architect of Historical Monuments in charge of the restoration, Frédéric Didier, commissioned Gérard Foucault* to define the hall’s lighting and to oversee the work. Cosil’s director, faithful to his work principles, proposed getting right to the essential, by offering the opportunity to view the hall’s masterpieces while respecting the hall and its artists. This modest, humble approach avoided the superfluous or modern simply for the sake of using it.

The aim of artificial lighting is to reveal the ceiling and tympanums by creating the impression that the chandeliers and candelabras cast enough light to see the artwork. Revealing them without accentuating them - they are sufficient in themselves - the visitor finds in them what he seeks and wishes to see. This discrete addition of electric light allows for a finer reading of the ceiling’s details and colors, spreading a soft, invisible, diffused lighting that dissimulates the stigmata of aging such as bulges and blisters.

After Frédéric Didier’s approval, numerous presentations, and day and nighttime trials, were presented to the scientific committee who then approved this lighting principal.

To answer most of the criteria requested, a special projector was defined and developed. This apparatus, hidden in the cornices, was studied with an eye on technical rather than esthetic performances, the obligations of the result being :

For conservation :

  • to weaken caloric emissions along the apparatus’ edges,
  • to eliminate U.V. rays by <400nm,
  • to not make holes in the artwork holding the lighting equipment,
  • to respect the recommended lighting levels,

And for the effect :

  • to limit differences in color temperature,
  • to avoid shadows caused by chandelier cords,
  • to conserve a definitive adjustment of beams when relamping,
  • to define a finished tint that fuses with the backgrounds,
  • to line up the lamps to avoid primary and secondary luminances,
  • to restore, via a light haze, the unity with the gold, reds and lapis lazuli of the skies which was rediscovered during restoration.

Throughout the 3 years of intervention, restoration and trials, the lighting principals were simplified and pared down. The ceiling’s painted canvases have rediscovered their original vivacity (see Hercules) and the number of light sources initially planned was reduced by 30%, a consumption of <10W/m².

The gold leaf naturally revived the cartridges and trophies, leading to the use of a single type of apparatus and single source for the entire ceiling.
In order to balance the lighting differences caused by the natural daylight, the program system uses lamps functioning at 80% of their initial value, while, in the evening their intensity drops to 30%.

The chandeliers and candelabras, part of the Château’s furniture, were restored and equipped with new lamps by a specialist.