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Van de Graaff generator spark close-ups
I suddenly got some inspiration to get back into shooting Van de Graaff generator sparks tonight, after a spontaneous idea on how to contain the discharges into a small area while still giving them enough energy to branch and have vivid main channels. This allows getting the DSLR close to the setup without the risk of it getting hit.
In short, I created a main spark gap by placing my smaller VDG dome about 5 inches from the large generator. This gap produces intense white-hot sparks that are, unfortunately, also straight, branchless and generally featureless. I connected a cable to the smaller dome and suspended it a few inches over a metal plate connected to the ground of the larger generator. Whenever the main spark gap discharges, it simultaneously flashes across the secondary gap I created over the metal plate. The secondary sparks are a good 3 to 4 inches long, and have detailed tourtuous and branching channels. The nice thing is that this is more of a closed circuit, with sparks neatly contained in a small area I can focus a lens on. The big generator can throw solid 16" sparks by itself in random directions, and bringing a camera close to it isn't safe (for the camera, that is).
Simulated miniature skyscrapers with antennas:
8-inch branched sparks between the two generator domes:
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