France, with over 100 natural caverns, drawing in more than six million visitors every year, is the number one venue for underground tourism in Europe. With such stiff competition, Choranche Cave, located in the heart of the Vercors reserve between Grenoble and Valence, pulled out all the stops to ensure visitors paid to enjoy its tubular stalactites – made from calcium and sometimes call ‘soda straws’ – above all others.
Late 2008, installation and integration expert Système Son, a specialist in distributing, designing, organising, selling and renting out sound and light equipment, won a 200,000 euro tender with its outstanding video projection solutions from Christie – global leader in diverse visualisation solutions.
"Powerful, bright, robust, reliable, easy-to-use… the qualities of Christie's solutions are recognised by the entire profession. Christie is a partner that lives up to its reputation: Christie's video projectors were an obvious choice for us," explains Philippe Armand, service hire manager at Système Son.
Christie - guaranteed living images for a perfectly immersive experience in the fairy-tale subterranean world
The display uses two Christie Roadster S+16K projectors equipped with Twist™ cards. This model boasts SXGA+ resolution (1400 x 1050) and brightness levels of 16 000 lumens. Featuring the 3-chip DLP™ technology with 0.95" DMD chips, the Roadster S+16K offers 90% brightness uniformity and a 1500:1 full field contrast ratio. The Christie Roadster S+16K comes with built-in handles, a new airflow pattern and multi-rigging points. Tipping the scales at a mere 63.5kg, it can be carried by just two people. It is designed for hire and use in any environment, and its 10-bit image processing capability raises the bar for actual image processing, colour accuracy and video realism. The onboard ChristieNET network interface allows for control of all the projector's functions over a network.
The Caves had previously be installed with a now outdated sound and light system and so the organisers were aware of the potential risks inherent in such a setup, particularly in terms of cold and humidity. With a 98% humidity rate and constant 10°C temperature throughout the year, the projectors needed the right enclosure. Système Son developed ventilated, heated and aerated protective casings (to meet seasonal variations) to keep the projectors at the same temperature and ensure maximum reliability in all circumstances.
Underground video projection - a real challenge
Overall installation began on 20 March 2009 and finished on 12 April, with the cave's constraints raising a real challenge. After taking down the previous system, the teams at Système Son started by changing where visitors initially enter the cave. Visitors previously watched from a concrete esplanade, but are now comfortably installed on a 60-seat terrace as "traditional" spectators thanks to the 200° panoramic view.
Above all, the teams had to comply with the installation's main prerequisite: for the image to do justice to the cave and vice-versa. Easier said than done, when dealing with the "crooked" walls of the cave: unlike the smooth, flat surfaces of a traditional outdoor architectural feature. The height difference of the cave walls in varied by as much as 15 metres. The imaginative work has gone to unprecedented lengths, producing exceptional quality rendering.
The projected images are received by two side screens measuring 28 metres wide by 14 metres high, corresponding to two distinct side spaces. Not projecting anything between the two screens gives a sense of depth and of the cave opening up. The onboard Twist™ card straightens out the image deformed by the rocky surface without any need to tweak the projectors.
44 light sources have been set up throughout the cave. 12 ADB Lighting profile spotlights (underwater projectors) have been installed to illuminate the basins alongside four 2 500W City Colors: in all, some 10 000 watts of light illuminate the water to produce a sublime effect. Machines are fitted with 1.2 lenses. In terms of sound, Système Son has gone for the d&b audiotechnik technology with a Dolby 5.0 system for a completely immersive experience.
The entire system is automated: when switched on, the DMX controller launches the three parts of the show in unison – sound, video and light.
Choranche Cave is now capable of producing stunning visual effects. For example, it has worked on creating the outline of a bat, which gives the impression of a fantasy world when walking through the Cathedral Room. Organisers are also looking to use the video projection technologies to screen works by artists and for organising various performances, such as concerts, live paintings and other artistically-innovative installations.
"We are delighted to lend our support to a new breed of show, where video projectors really come into their own. We are helping to drive development of Choranche Cave by providing the very best in projection and visualisation technology," explains Olivier Collet, sales engineer France in charge of the fixed installation contract.
"The quality of Christie's equipment and the installation work by the teams at Système Son has given us real added value in the tourist cave market. Not only do Christie's solutions give us a technical advance, but also a cultural advantage by showcasing the cave and its treasures," concludes Laurent Garnier, Director of Choranche Cave. "We now have a real competitive advantage and have seen our main wish come true of thrilling those in search of fantasy and magical experiences, while reaching out to a new public that enjoys seeing images used in an original way and in different settings."
The all-new sound-light-video show in Choranche Cave was inaugurated on 24 April.