Visualizing the invisible II
The goal is to visualize the operational volume of a RFID reader. Where it lights up a tag could be powered by the reader magnetic field.
This is an attempt inspired by this work but the technique is a bit different.
They drive a LED when the reader can read the tag while here, I mounted directly a LED on a tag (a Touchatag to be exact) after having destroyed the tag chip. So the LED gets powered directly by the available field: the response time is dramatically improved and LED intensity shows the field strength.
Tag+LED are then simply suspended by a wire like a radiesthesist pendulum in my hand and I move it around while shooting with long exposure.
Wikipedia: Radiesthesia is the paranormal or parapsychological ability to detect "radiation" within the human body. According to the theory, all human bodies give off unique or characteristic "radiations" as do all other physical bodies or objects. A practitioner of radiestheisa believes in his or her ability to detect the interplay of these radiations.
Mmm actually we're not that far ;-)