Dr. Resonance wrote: > You might also note in your analysis the average forking in a lightning > discharge is 16 degrees. This also applies to other forms of high voltage > discharges as well. Interesting observation. I note in that picture another feature that I frequently see in spark images: There is a dark area at the borders of the image of the spark channel. Imaging artifact, or some real phenomenon? Antonio Carlos M. de Queiroz