> Motivation
> Example Movie
> Comment
> Conclusion
> Related Experiments
> Setup


Performance Photo

Screenshot

> Top

 

Motivation

Motion blur refers to the effect of a moving object appearing blurry on a photograph captured with a long time exposure. The motion leaves a trace. These traces give visual clues for the reconstruction of the motion. Thinking of a long time exposure covering the whole performance, these traces are the recorded memory of the motion. One can prevent the image to be permanently overwritten with new information by letting just small parts of the body leave these traces. This reduces the visual complexity of the image and forces the dancer as well as the audience to concentrate on a certain part of the dancer's body.

 

> Top

 

Example Movie

Stage View
Computer Image
The dancer is moving slowly from the left side of the camera frame to the right and back again. On the captured image only the area around his right arm is seen and is left over as a video-trace, a record that later is also erased and rewritten by a new movement.

 

> Top

 

Comment

This experiment was for us more interesting in terms of analyzing its visual result than in the quality of movement that was triggered by it. Like writing with a pen on paper, a natural way to move through this set-up is from one side to the other. The marks that are left over give an indication of what the movement was and where in space it took place.

The aspect of erasing and overwriting ones own traces, and the fact that a fast movement only leaves a thin and transparent trace, informs the decision about what kind of motion you engrave into the room and therefore how permanent and how visible the traces will be left on the screen.

It was interesting to be confronted with the image that stayed on the screen at the end of each run and analyze it. Certain moments of the movement-sequence were left as an engraving, others not. With some images we were able to recognize and identify when and what Nik had been doing at that point. Other images we could not put in relation to what we remembered about the sequence Nik had just danced.

Although the traces left on the screen are frozen and still, they nevertheless comprise a sense of motion. The circle of the sensor (attached to Nik's right hand) can be seen clearer when an already engraved image is erased and overwritten. Commonly dance is regarded as transient with only the brief existence of the moment. What stays on the screen in this setup after the dancer stops and leaves is a memory image of this brief and transient quality of dance.

 

> Top

 

Conclusion

Since in this setup a circular portion of the live video image overwrites the canvas with a certain transparency, it is possible to erase parts of the image already written. The result becomes a fragmented writing and not a complete and continuous one as in and . Thus it preserves only rudimentary information about the past motion and it turns out to function more like a painting device rather than a notation or comprehensive remembrance mechanism.

 

> Top

 

Related Experiments:

 

> Top

 

Setup

 


Hardware:

  • Graphics PC with Video Capture Card
  • Projector
  • Polhemus tracking system: 1 Sensor
  • Video Camera



Configuration:

  • The image displayed on the Projection Screen in a sense develops like a drawing. At the beginning the image background is a full video frame of the empty room captured by the camera in front. Then a spot, which is just showing a circular part of the live video image, continuously paints on top of the background image.
  • The Video Camera is facing the dancer and transmits the live video image to the graphics computer. This video image is masked by a round spot as illustrated in the Technical Screenshots below. The live image and the background image are superimposed within an area between an inner and an outer circle visible in Technical Screenshot 1.
  • The Sensor controls the position of the spot on screen. Thus the dancer can control which fraction of his body appears within the spot on the screen. In the recording we attached the sensor to the dancer's right hand.

 


Technical Setup

Spatial Setup

Technical Screenshot 1


Technical Sceenshot 2

> Top