History: Spirit Photography By William Hope

On 4 February 1922 the Society for Psychical Research and the paranormal investigator Harry Price attempted to prove that Hope was a fraud during tests at the British College of Psychic Science. Price secretly marked Hope's photographic plates, and provided him with a packet of additional plates that had been covertly etched with the brand image of the Imperial Dry Plate Co. Ltd. in the knowledge that the logo would be transferred to any images created with them. Unaware that Price had tampered with his supplies, Hope then attempted to produce a number of Spirit photographs. Although Hope produced several images of spirits, none of his materials contained the Imperial Dry Plate Co. Ltd logo, or the marks that Price had put on Hopes original equipment, showing that he had switched prepared materials containing fake spirit images for the provided materials. Price later re-published the Society's experiment in a pamphlet of his own called Cold Light on Spiritualistic "Phenomena" - An Experiment with the Crewe Circle."
In 1932, Fred Barlow, a former friend and supporter of Hope’s work and also the former Secretary of the Society for the Study of Supernormal Pictures, along with Major W. Rampling-Rose, gave a joint lecture to the Society for Psychical Research to present findings gleaned from an extensive series of tests on the methods Hope used to produce his spirit photographs.