Kirlian photography is a method of photographing energy, making something typically invisible visible. As emotions between people become charged with different vibrations, the energy between them changes, and Kirlian photographers have caught the change and interchange of energy in Kirlian photographs.
While many skeptics claim that nothing at all can be proved with the Kirlian method, believers say that Kirlian photographs capture the energy emanating from the object being photographed. As I relate in my article, Kirlian Photography Shows Spirit Connections in Close Relationships, I wonder why paranormal investigators don't use Kirlian photography in their attempts to prove the existence of spirits. (In that article I link to another article about Kirlian Photography that discusses how the Kirlian method came about.)
It seems to me that if Kirlian photography showed the existence of spirits, paranormal investigators would include it as part of their investigative tools.
Kirlian photography is a subject that is more paranormal than it is metaphysical, and in my article Paranormal and Metaphysical: What's The Difference, I explain the distinction (or lack of distinction) between the two.
While metaphysics concerns itself with the more spiritual aspects of our existence, the paranormal is more concerned with the afterlife and has a "creepiness" factor that metaphysics doesn't. In other words, if you're thinking "ghost," you're thinking paranormal; if you're thinking "spirit," you're thinking metaphysical.
As I mention in the article posted above, paranormal falls under the umbrella of metaphysical, so Kirlian photography would be an interest both paranormal and metaphysical. To learn more about Kirlian Photography, I've included a link to a book with the same name.