After some experimentation I feel that the sense of field of one ultrasonic sensor is not going to be wide enough to reliably control the work. With this in mind I have also been thinking about how to use a space and its dimensions to my advantage.
This idea uses two ultrasonic sensors in a space that is 3 metres long, and 1 metre wide (enough room to comfortably fit one person) the work is shown on a 20” (or so) TFT monitor set at the furthest point away from the entrance. The sensors are mounted opposite the screen (my other ideas have placed the sensor either above or below the projection) I’ve found that the sensors work best when they are placed at upper body height, so it is not possible to have them on the same wall as the work for their positioning would be quite obtrusive, also placing them on the opposite wall means that they will distract less from the work, keeping the technology hidden as much as possible.
I want this to be an investigative environment, I feel by using a relatively small TFT as opposed to a large projection the viewer will be more inclined to approach the screen therefore walking the length of the installation, this will mean that the sensors can use their optimum range to maximum affect and hopefully the space will be more successful for it.
When there is no presence in the room a video plays at un-identifiable speed. When a person enters the space the video will slow down and change. The two sensors will control two separate videos composited on top of one another. They will also handle separate audio.
Using your movement you will have the ability to stop and start the audio and two videos either independently or simultaneously (depending on your distance and position within the room)
For me this process has some interesting connotations, firstly, by having an element of control over when the video is played or stopped gives the viewer the opportunity to inspect the footage and see imagery within it that would have otherwise been lost. This relates to how we experience the non-space at speed preventing us from ever truly identifying with it.
And secondly, with each individual having an influence over whether the videos are playing or are stopped means that the composite will progressively change. By the end of the show you would have an alternative edit or mix, a mix that has been shaped by the presence of the people that chose to inspect it. It would have shaped its own identity.