Spirit photography became popular during the mid-19th century with the introduction of film cameras and the rise of Spiritualism, a movement where practitioners attempted to speak with the dead. This theme remains popular in lots of magic and mentalism.
The Spiritualism era is well known for its seances and mediums who in various ways supposedly communicated with the deceased. Perhaps its best known proponent was Sir Arthur Conan Doyle, the author of the Sherlock Holmes stories. And perhaps its best known critic was Harry Houdini, who constantly exposed spiritual frauds as he himself attempted to reach his deceased mother.
Critics have long lambasted spirit photographs as proving nothing and cite double-exposures, doctored negatives and darkroom techniques as viable explanations. Some well known photographers of the Spiritualism era were proven to be fakes.
