Feedback: Liquid Light

Ron Pellegrino, 9/11/00

The title, LIQUID LIGHT, describes how it feels, literally by hand, to sculpt these video light forms in visual music counterpoint to sonic music. The first part of the excerpt is created by entering into the light path between the camera and the monitor with a small handheld magnifying glass and playing the video light stream in visual music counterpoint to the sonic music by virtually drawing it out of the screen as if it were a viscous liquid. (Image set 1) The last part of the excerpt provides a good sense of how the video light in this feedback system responds to manipulation as if it were viscous liquid. (Image set 2)

Image set 1: drawing out light with a magnifying glass

Image set 2: manipulating light by hand

In LIQUID LIGHT all the manipulation is done by my left hand while my right hand is playing a video camera balanced on my right shoulder. The camera technique is one I've been honing since the late 1980s when I added real-time videography to my performance-multimedia shows. In actual performances my left hand is just as likely to be manipulating a computer keyboard, a mouse, or switches and sliders of various pieces of video and audio gear while my right hand tends to the video camera.

I was introduced to video feedback late in 1971 when I visited the National Center for Experiments in Television (NCET) in San Francisco in preparation for a research stint there. The artists at the NCET (and, I later discovered, other places) referred to feedback as a video whore - it was technically easy to do so anyone could do it thus the artistic value of anything done with it was greatly diminished. I've never accepted that notion because the logic is flawed. Anyone can get sound out of a piano but that doesn't devalue good piano performance. The same logic holds true for video feedback. Furthermore I've often sensed the implicit desire by artists working with emerging technology to keep the circle of users as small as possible - the more exclusive the access to the technology the more valuable the output of that technology, so the thinking goes. Flawed thinking again. A far more productive attitude is to make emerging technology affordable so more people can access it thereby adding their experiences and perspectives to the evolutionary mix. The upshot is not to let anyone discourage you from exploring video feedback systems. The exploratory returns are manifold.

The simplest video feedback system is a video monitor (A) and a video camera (B) cabled back to the video monitor (A). The monitor (A) generates light (photons) that are picked up the camera (B) then returned by cable to the monitor (A) to create a recurring loop (A to B to A to B to A etc.) of electronically generated light (emitted from the monitor) and electronically represented light (transduced by the camera into electronic signals).

The basic material (photons) of the loop is created by an electron gun shooting an interlaced stream of electrons onto a phosphor coated glass surface (the screen of the video monitor). When struck by the electrons the excited phosphors emit photons (light particles/energy) that are picked up by the electric camera and routed back to the electron gun to perpetuate the loop.

Fluid dynamic light images are created via the feedback process. In the simplest video feedback system the dynamic forms of the images are subject to combinations of fixed and continuously variable settings of the controls on the camera (focus, zoom, targeting, sensitivity, tilt, pan, etc.) and the monitor (brightness, sharpness, contrast, color settings, etc.) plus the distance between the monitor screen and the camera. More complex systems can be designed by adding physical objects and/or optics between the camera and the screen as well as electronic objects - circuits or algorithmic processes (computer hardware and software)) - between the camera output and electron gun input - the monitor. The greater the number of objects added to the system the greater the number of dynamic image possibilities.

In video feedback performance, light images are sculpted by playing sets of system variables usually within well defined ranges previously determined by experimentation and aesthetic judgements. In effect, the sets become variations of a visual music instrument - virtual modules for creating visual music. And just like building skill on a traditional music instrument, intelligent practice on those virtual modules points in the direction of perfection, a notion best viewed as a cloud of possibilities. My personal inclination is to search for the "voice" of the system - what seems expressively natural for it. That search is an intuitive process of playing, tuning, and winnowing until the system gels - seems to achieve a level of coherence that makes it performable (a very personal judgement that improves with time, thought, and practice).

There's a conversational quality about the process of video feedback that gives it added value for performance artists - especially in the early experimental stages when you're cultivating familiarity with the personalities of the instruments. Like music, the imagery spins out in time. Like music, its morphological context is determined by its recent history and probable future - what preceded it and what may possibly follow it. Contributors to the conversation are the video monitor, the video camera, the performer, any physical or electronic objects included in the system, and the psychological context (public performance, company of friends and family, solo exploration, etc). The performer leads the conversation but the other contributors definitely have their own inclinations, in effect, their own minds. To make the creative process work the performer must respect those minds and tune to the combination of their idiosyncrasies.

Since I added video to my visual music research in 1972, my video feedback systems have been used for compositional tuning exercises, for pure exploratory pleasure, and for demonstrations of how a fundamental life principle can be a vehicle for performance art. They've also been integrated into my performance-multimedia systems. Plus, the feedback process is a karmic lesson demonstrating that where you've been and what you've done strongly influences where you're going and what you're going to do. In other words, the feedback process ephemerally embodies a memory integrated with its evolving form. To play the leading edge of that evolving form you need to need to be conscious of what you've done to get there and of what the possibilities are beyond the edge - it's a tuning exercise in integrating past, present, and future. There's a wonderful book, THE LIVING ENERGY UNIVERSE, that's packed from beginning to end with very convincing arguments for viewing the principle of feedback as the glue of life operating on all levels from the microcosm to the macrocosm - from quanta to the universe. If you've managed to get to this point in this description, chances are very good that you'd find this book to be inspiring and enlightening. I did. That's why I posted the excerpt from LIQUID LIGHT.



Please note that video on the internet in September of 2000 (when I started posting video excerpts) still has a long way to go for great image and sound quality. Nevertheless, even under current conditions there are ways of optimizing the internet video experience.

Ways to get the best results from this video file:

  1. Setting your monitor to a resolution of 640 x 480 will provide the largest image with no distortion. Finer resolutions will also work; the screen will just be smaller and the image compromised somewhat.
  2. With some browsers, Internet Explorer 5 for example, you can resize the the video by grabbing its window in the lower right hand corner and pushing and pulling it. If you resize the image adust your viewing distance to the monitor accordingly.
  3. Be sure you play the music on a good sound system; the speaker built into your computer is as bad as audio systems get. For less than $100 you can get a decent stereo sound system to connect to your computer and your listening pleasure will be greatly enhanced. For less than $50 you can buy decent stereo headphones. Never listen to music over the speakers built into your computer; they should be illegal.
  4. Video files are long, which means downloads are long. Let the file download in the background while you're doing something else with your computer. Or while the file is downloading take a walk and see what birds are playing in your yard or out on the street. If your sound system is turned on, the music will begin playing as soon as the video file is finished downloading. That's a good way to remind yourself you started a long download especially if you start working on something else in the meantime.
  5. To play the video you should have QuickTime installed. If you don't, download it at no cost from Apple.



To download the video excerpt from LIQUID LIGHT (15.5 MB) click here. Be sure to download long video files in the background while you're doing other tasks with your computer or away from your computer.



Go to this page for links to more video excerpts.



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