Is Spirit Photography Real?
In the early days of photography most customers were very naive and unfamiliar with the ways in which photographic images could be manipulated. So a photographer could promote themselves as being able to take a portrait in which one of the deceased might spiritually appear. They would then introduce a likeness by a method such as double-negative. What is especially cruel is how these charlatans would exploit people grieving the loss of a spouse or other family member. Famously including Mary Todd Lincoln, the widow of assassinated president Abraham Lincoln.
William H. Mumler (1832-1884)
Mumler was a spirit photographer who operated in the United States, predominantly in Boston and New York. He is best known for producing a photograph for Mary Todd Lincoln showing the "spirit" of her husband, the late Abraham Lincoln (shown right). Mumler profited greatly from creating photographs for families who had lost family members to the American Civil War.
He was ultimately charged with fraud and, while not convicted, discredited and disgraced. Testimony had cast light on the fact that some of the "spirits" appearing in his photographs were living people, and others appeared in more than one picture as the spirits of different deceased people.
It may seem strange that people accepted these faded images as their deceased relatives, but the 'spirit' pictures were often indistinct and most customers were inclined to believe in the validity picture that they commissioned at great cost. Mumler destroyed all of his negatives shortly before his death, but many prints still survive.
Frederick A Hudson (1812-????)
Nor was this purely an American phenomenon. Frederick Hudson is considered the first British spirit photographer. His entry into this activity was encouraged by potential customers who had heard of spirit photographs and wish to commission their own. Samuel Guppy and Agnes Guppy-Volckman were his first spirit photography clients who were willing to pay generously for the questionable comfort of a picture of the spirits of the dead..
Hudson had particular success producing accepted likenesses of decedents that resembled no picture known of them, and he was also caught in obviously fraud on several occasions. Nevertheless he managed to earn both wealth and fame from his willingness to product these fraudulent images. His most famous work was produced throughout the 1870s and can still be found in collections of photography in major museums.
William Hope (1863-1933)
Spirit photography continued into the 20th century and began to take on a less formal and artistic form. looking less like romantic oil paintings and more like candid family photographs with more of an emphasis on capturing a likeness of the deceased person. For example, William Hope practiced spirit photography in Crewe, England. As with Mumler, Hope's business was buoyed by families bereaved by war, in this case World War 1.
Hope was investigated as a fraud in the 1920s. Evidence that he replaced clean plates with others, presumably prepared earlier with the ghostly image, convinced all but his more committed followers that the practice of spirit photography was deliberately fraudulant.
Ghost Photography
While there are very few people working as spirit photographers any more, people still do feel that they may have caught a ghost on film. Although this is typically more a case of a flaw or reflection in the picture and a lot of wishful thinking--or a deliberate hoax of a more up-to-date kind.
Definitely Not Real
Spirit photography has effectively become extinct as the general public became more familiar with how photographic images can be manipulated. Even the most credulous modern client is not going to be convinced by an image that is identical to an existing photograph of the deceased, or does not actually resemble them. So you would have to search long and hard to find anyone who believes in staged studio ghost photography, although the idea does linger on in the phenomena of aura photography or candid ghost photography.
However the particular combination of widespread grief and technological naivety that allowed spirit photography to flourish after wars in the early modern era has passed, and this particular paranormal scam seems to be safely a thing of the past.