Right off the bat, let’s specify that spirit photography was, is and always will be bogus. It is simple trickery accomplished using double exposure. At least, that’s what William Mumler discovered in the 1860s when he accidentally used double exposure and placed another person in a photograph of himself. He quickly realized the potential value of his new technique and started promoting it as spirit photography which could be used to capture images of ghosts and other spirits.
Mumler and later spirit photographers like William Hope retained loyal followings even though it didn’t take long for skeptics to figure out and expose how spirit photography actually worked. Prominent doubters included P.T. Barnum and Harry Houdini, both of whom created their own spirit photographs to show exactly how it was done. It seemed as if each time one spirit photographer was exposed as a fraud, another one took his place so the practice remained popular for decades. However, just because these photographs don’t actually show us a glimpse into the spirit world does not detract from their historical value.