Alex Carpenter (2010)
INTRODUCTION / AUDIO DELAY
The Live Video Delay System essentially realizes a visual analogue to an improvisational approach I've been using in solo audio performance scenarios since 2003 (e.g. Deep Golden Flourish, Excavation Patterns). These scenarios involve one or several long audio loops (5-23 seconds), which begin as near-blank “canvases” and are built on in real time via a delayed playback/response cycle.
This process is different to perhaps more standard layered looping processes in that it does not begin with a structural foundation in place, or in mind. Rather, the structure evolves from – and is determined by – the layering process itself.
I like to think of this performance activity as a kind of “tending.” It is not the willing-into-existence of an already known thing, but a careful and reverent listening and responding, which ensures the thing grows from, and stands on, its own foundations.
What results is a growing sonic “organism” that is neither purely a product of the performer, nor completely reducible to the processing mechanism. The performer contributes new material, but he/she is always guided by what is played back, and what is played back is always the sum of his/her previous recorded “guidances.” In another sense, you could say the organism's path of development is shaped by its own previous incarnations and memories, and the impression they have upon the observing performer.
Taking this analogy further, perhaps there is a kind of dangerous seduction at play between the organism and the performer. The organism needs to seduce the performer in order to grow and flourish, but peril is always present in that the performer may at any time obliterate the organism, either by not responding sensitively or by exerting his/her power to reduce it to his/her own will.
TRANSLATING TO VIDEO
The idea of utilizing this way of working visually has always appealed to me, but for a long time the conceptualization of a problem-free visual system eluded me. I knew I could probably realize something similar by editing video in layers, but this would preclude the possibility of real-time reaction, which was a vital part of the process. I also suspected there may have been a way of realizing the process through graphics software, which I wasn't exactly closed to (and still aren't), it just seemed to remain a last resort in my mind.
Mainly, I wanted the system to be highly responsive and able to capture nuance. I'd learned from my audio work that subtle differences in pitch, articulation, intensity, etc. often played a vital role in setting the course of structural development, as if in these nuances the organism-to-be suggested itself. So it was important the visual system was similarly responsive. Digital work flow is indirect by nature. It is not that nuance cannot be achieved, but that the route leading there is often long and convoluted, with many stages. In my case, this posed too much of a threat upon the required immediacy and spontaneity of response.
My ideal was really some form of “drawing” that could be captured, looped and built upon. I eventually realized the rudiments of such a system could be achieved with two camera-projector chains; one dealing with the feedback loop, the other dealing with the addition of new material. The feedback chain's camera would simply need to see the screen, then output imagery back to the projection surface after a certain amount of time (via a delay line). The second camera would need to see the artist's canvas and output imagery (with no delay) to the same projection surface, thus infiltrating the loop. But several problems remained. Aside from the artist's hand/pen being in shot, there were issues of visual clarity to address.
Layering projected video is not like layering sound. A sound in an electronic signal chain stands out against a backdrop of (virtual) silence. But a projected video subject (e.g. a dot) does not stand out against a backdrop of “no light.” Even a black background is made up of light. Thus, each additional layer would undoubtedly result in a greater build up of artifacts, noise, and in the case of brighter backgrounds, colour saturation. In other words, contrast and subject-definition could very quickly be compromised.
The task then essentially became figuring out how to impede the build up of artifacts as much as possible. Inverting the white background / black subject paradigm seemed to be a step in the right direction. But the real breakthrough came when I realized an even sharper isolation of the subject could be achieved if it was drawn in a more vivid colour and then captured through a corresponding colour lens filter. Colour lens filters pass certain colours while blocking others. This means a heavy red filter would pass a red subject with great clarity along with red noise components only, significantly reducing artifacts overall. Using red filters at both stages of capture (and possibly projection also), as well as increasing camera exposure, seemed to promise a more than workable system.
The idea of using a focused red laser as the image source seemed to not only reinforce this goal of artifact-reduction, but also resolve the hand-in-shot issue, and eliminate the need to deal with line-trail (i.e. having to clear the canvas each time new material was added).
THE SYSTEM
How it works: Camera 2 sees the performer’s laser activity on the black surface and when Fader 2 is opened the image is projected from Projector 2 onto the projection surface. Camera 1, which is trained on the projection surface, sees the image and sends it to the DVR. The DVR delays the signal by a given period of time, then sends it to Projector 1. Projector 1 projects the image onto exactly the same projection surface, the image is seen by Camera 1 and the whole delay cycle begins again.
In effect, what is set up by Chain 1 is a “loop,” even though technically there is never any true repetition of data. Camera 1 sees at first a performance, then a playback, then a playback of the playback, then a playback of the playback of the playback, etc. If the performer was to stop contributing new material (via Chain 2), this “loop” would essentially be repeated continuously with no change other than generational loss.
The monitor and Fader 1 are both necessary supplements to the DVR. Originally I imagined the signal delay would be provided by a standard video delay line, but when I learned such units cost upwards of $1000, Jim Lyons at Allen Avionics in
TEST SESSION, MELA FOUNDATION
The first test session of this system took place on September 21-22, 2009, at the MELA Foundation in
Decay & Depth
Initially, I was disappointed to learn the precise wavelength of the red laser’s output was being distorted somewhere in the circuitry of the camera, resulting in too significant a loss of brightness through the projector’s filter. Essentially, the image, by the time it reached the projector, was no longer a pure red, and thus could not pass through the projector’s filter unaffected. But I soon learned such filtering was basically unnecessary, since, surprisingly, the camera filters provided more than enough isolation of the subject.
Still, colour was being very slightly compromised somewhere in the chain, and as a result the image was losing a small shade of brightness each time it passed through the camera’s filter. It struck me, though, that this “decay” was not necessarily a flaw. Although something was lost in terms of the longevity of the loop, something was gained in terms of visual depth. Instead of all layers remaining at equal brightness, older layers seemed to retreat further back and occupy a different plane to newer ones. An extra dimension of depth presented itself.