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États et intervalles

François Quévillon




États et intervalles is an audiovisual interactive installation that explores the perception of change, the instability of matter and chain reaction phenomena.

As the viewer enters the corridor where it takes place, his movements in space influence the speed of the video sequences projected and the composition of the soundtrack. On a rear-projection screen, a solid block of ice turns gradually to water, then to gas. The viewer’s behavior is reflected by the artwork through a relationship that oscillates between action and contemplation.


Photo gallery



François Quévillon is an undergraduate student at the École des arts visuels et médiatiques at UQAM. After studying graphic arts at college and being trained in multimedia, he has worked on a variety of illustration and computer graphics projects since 1997. His artistic work focuses mainly on interactive works and video installations. Using digital video, computer generated images and sound processing, he manipulates and transforms audiovisual elements by exploring their inherent structures and temporality in order to reveal other senses related with the perception of change and the instability of matter. His video installtation Defrost was awarded the Jury's Prize in the New images category of the 2002 edition of Vidéaste recherché(e). He lives and works in Montreal, Quebec.

Technical specifications

An infrared video camera concealed in the ceiling watches over the corridor at the end of which stands the projection screen. As soon as a viewer steps in, he activates the audio and visual components of the installation. The reactions intensify as he gets closer to the screen and as his movements increase. The data obtained by the camera is accumulated and interpreted in order to adapt to the viewer’s behavior.

The viewer’s movements control the scrolling speed of the video images and compose the soundtrack that can be heard through 4 loudspeakers and 1 subwoofer. In the absence of activity in the interaction zone, the image pauses and a soundtrack resulting from residues of past gestures is audible from the behind the screen. A sound effect processor is used for these 2 audio channels. A long-term delay effect (a slow-fading echo at a one-second interval) layers the sound and accentuates the temporal aspect of the work, and a pitch-shifter divides the soundtrack into two distinctive spaces: high-pitched and ephemeral sounds are diffused in the interaction zone while the low and rhythmical frequencies are situated outside the space, behind the rear-projection screen.

Different algorithms that respond to the viewer’s position in relation to the screen control the video sequences and sound samples. As he approaches the image and loses the overall perception of it, the video sequence accelerates and the soundtrack becomes saturated, perhaps even noisy. The viewer is thus placed in a situation of attraction/repulsion towards the piece, controlling it’s unveiling as well as it’s dissipation.
The images are rear-projected on a vertical screen of a 5:8 ratio taking up the entire surface at the end of the corridor. Although the size and shape of the screen and corridor can be adapted to the exhibition space, the corridor must have a minimal width of 5 feet to avoid too intense and claustrophobic sensations.

  • Development platform: Power Macintosh G4 — Apple
  • Authoring system: Director 8.5 — Macromedia
  • Equipment: Apple Power Macintosh G4 computer, monitor, data projector, wide angle infrared video camera, Digitech S200 effects processor, Behringer Eurorack analogue mixer, 4 loudspeakers and 1 subwoofer.


During the prototype presentation, the interactive experiences observed seemed to be more satisfactory on an audio rather than visual level. The closer the viewers came to the screen, the louder and denser the soundtrack became. Even though there was a constant reverberation coming from behind the screen, the two speakers inside the environment were silent in absence of movement. This change of intensity in the soundtrack made obvious the direct relationship between their position in space and the sound variations. The sound aspect of the work was rich in terms of variations and possible combinations and prevented the viewer from being caught in a closed circuit. A clear dialogue took place.

In terms of the visual aspect of the piece, the influence of the viewer’s behavior on the temporal changes in the video sequence was somewhat more ambiguous. This might be caused by the fact that the images representing a transitory phenomenon on a loop were too abstract for the context of this work. In spite of the 22000 images that constituted it , the video sequence was more limited in terms of interactivity because it evolved within a linear structure, pausing and scrolling at a variable speed. The viewers could walk in the environment at any stage of the video loop (triggered by other viewers), but the best situation was to start the interaction at least one minute after the previous interaction had ended. This left enough time for the video sequence to go back to the beginning where the water was at its original frozen, solid state. The installation was optimized when only one viewer at a time interacted thus creating in a more intimate and relevant relationship.

Two problems occurred during the presentation of the prototype. First, people tended to contemplate the piece from a distance rather than “break the ice” and walk into the corridor. To encourage viewers to enter, the interaction zone delimited by the infrared camera should start outside the corridor, about tree feet from the entrance. This way, the viewer’s presence would influence the piece earlier on, and at a greater distance, and in so doing would allow the participant to feel more progressive variations.

Presenting the piece États et intervalles to the public was an experience that questioned my own conception of interactivity, which I realize must clearly differ from the way I approach video production. On this topic, David Rokeby stated that “rather than presenting content, interactive media have the power to present modes of perception and action.” Thus, the audiovisual content must be closely adapted to this in order to keep the emphasis on the relation between action and response, which, to me, is the most important part of the experience.


HomeProjects — États et intervalles

© Interstices : Groupe de recherche et de création en arts médiatiques, 2010
© Interstices : Media Arts Research-Creation Group in 2010