Wearable Computing - Technology

Flash Lamps for Professionals - Links

Xenon strobe, flashlamps, flashtubes, etc.

The original motivation for the invention of the wearable computer was for mediated reality, and to experience the world in a different light. It was the desire to see our everyday world in a different light, that led to the invention of the Reality Mediator (RM).

A discussion of wearable computing would not be complete without a look at electronic flash systems, and their control by wearable computers. Early on, I created a wearable photographic lighting studio. This led to a genre of photographic imaging I called "dusting". Through a number of exhibits of this work in galleries in the early 1980s, this genre of cybernetic photography became more well known. By the summer of 1985, along with a solo exhibit I had at Night Gallery in Toronto (185 Richmond Street), I had unwittingly become a "cyborg" performance artist. This arose as various groups asked me to come and take cybernetic pictures with my wearable computer, and it became clear that they enjoyed watching me take the pictures as much as they enjoyed the final result. Throughout the 1980s I did numerous pictures for hair salons, musicians, and other arts groups, and found myself creating a "cyberfashion" movement with wearable computers. I had not intended wearable computers to be art in and of themselves, but for the art that they produced by way of pictures.

Cybernetic flash

By "flash" I don't mean "Macromedia" or "compact flash memory", but, rather, a light source that comes on briefly yet brilliantly. A flashtube is a gas filled tube, usually filled with xenon gas, to which a high voltage is applied via electrodes at opposite end, while an even higher trigger voltage is applied. Electronic flash, invented by Harold Edgerton, has remained essentially the same for more than 50 years. While nearly everything else, such as computers, radios, televisions, etc., has changed, flashtubes remain basically the same.

A series of cybernetic photographs were taken in Edgerton's lab, approximately three years after his death, to capture the lab exactly how he had left it, prior to the renovation of the space and to its modernization (getting rid of the old flashtubes and installing computers and digital imaging software, etc.). This series of pictures formed an exhibit entitled Microseconds and Years which was exhibited in the early 1990s at MIT, and again opened on exhibit at the Olga Korper Gallery in Toronto, July 6th, running until August 16th, 2000. The images depict flashtubes glowing through the dusty, forgotten veil of years gone by. The glow of the forgotten instruments of the past calls to mind the passage of time in a place where instruments for stopping time were invented. The years of dust on the forgotten instruments of the past are juxtaposed with the microsecond time scale in which they were intended to operate.

My favorite flashtubes, such as the FT-24 and the FT17-30, are from the 1930s and 1940s. The FT-24 was used by Mili for his famous pictures in Life magazine, wheras the FT17-30 was developed for aerial photography, to light up the beaches of Normandy for reconaissance pictures prior to the D-day invasions. As far as I know, the FT17-30 is the world's most powerful flashtube. A closed-end version, the FT623, is essentially equivalent except for the glass cover being closed at the end.

The FT17-30 (and FT623) operates at 40kJ (40,000 watt seconds). I find it works best with around 4000 volts on the mains, and triggers nicely between 20kV and 30kV. I generally run it from a backpack worn 4000 volt power supply, with external capacitors carried separately. Preferably the pack is powered by a small chainsaw or weed-eater motor running a small generator, rather than from a battery. I have the lamp mounted in a 30-inch highly polished reflector with a mirrorlike finish. I have two handles on the reflector, with a keyer on the right-hand handle, and a cursor control device (predecessor of the mouse) on the left-hand handle. With this system, I can walk around in a large city, illuminate tall skyscrapers, etc., and "paint" the entire city with lightvectors.

The early rigs were not entirely practical by today's standards, so you may want to take a look at some modern electronic flash systems

Acknowledgements: Thanks to Bran Ferren for help in obtaining a flashtube from Los Alamos Labs.

Xenon strobe, flashlamps, flashtubes, etc.

Cybernetic flash

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