Photography has been associated with death from its outset. Since the Spiritualist movement, which began in the 1850s, began inculcating the notion that the spirits of the dead could be called back from the beyond for an occasional chat, it was probably inevitable that mediums would use photography to “prove” they could contact the dead. It is shameful that amid the emotional turmoil caused by the Civil War photography was suborned to such low ends, but it was photography’s reputation for veracity that made it such a valuable accomplice; alas, long before Photoshop there were ways to dummy images.

Maybe it is in the very nature of photography, the way lifelike simulacra are created in the pitch-black chambers of the camera and the darkroom, to have about it an aura of magic, a hint of the uncanny, even of something forbidden. You can see for yourself in “The Perfect Medium: Photography and the Occult” at the Metropolitan Museum of Art. Then again, in this exhibition, seeing is not necessarily believing.

The exhibition is divided into three sections: Spirits, Mediums, and Fluids. The first section has the good stuff, pictures of clients who came to be photographed and were rewarded by having a spirit captured in their portrait. These are not poor people: At a time when photographs could be had for two bits, a spirit photograph cost 10 bucks with no guarantee of success.

William Mumler (1832-84) of Boston has the distinction of being the first photographer in America to practice this art. He claimed to have stumbled upon it; that is, one day in 1861 he took a self-portrait and, lo!, there beside him in the print was the shadowy figure of a young woman. Someone had to explain to him that this was a spirit. Once business picked up, his wife Hannah worked with him in the studio. Conveniently, Mrs. Mumler was a medium whose entrance into the studio was often accompanied by raps across the floor. Occasionally, the camera would “dance.”

In a typical Mumler photograph, an unexceptional portrait also includes a vague, pale figure standing behind the subject. The spirit figure sometimes has its hands on the shoulders of the subject, as in the famous “Mary Todd Lincoln with the spirit of her husband, President Abraham Lincoln” (1870-75). (Mrs. Lincoln, of course, went in for this sort of thing, was rumored to have had seances in the White House, and grieved perpetually.) “Master Herrod with the spirits of Europe, Africa, and America” (1870-72) shows the talented young medium in a trance state that called up representatives of other spiritualist cultures. This picture, along with “Master Herrod and his double” (c. 1870), was advertised for sale by Mumler in the Religio-Philosophical Journal.

Mumler got into trouble when a client recognized the spirit in his picture as a woman he knew who was very much alive. The photographer was acquitted after a sensational trial in 1869, when the judge ruled the prosecutor had failed to prove fraud, but the bad publicity did not help him, and he eventually chose another career path.

There are several pictures in this section that spoof spirit photographs, and my favorites are Andre-Adolphe-Eugene Disderi’s “Elie Cabrol and the Spirit Apparition of the Vicomte de Renneville” (1859) and Eugene Thiebault’s publicity photograph: “Henri Robin and a Specter” (1863). In the first, a sequence of six shots, the two sartorially resplendent friends pose singly and together, except that in two shots the Vicomte appears as a faded spirit and is naked; he is, however, wearing a helmet and holding a little metal shield.

In the latter, Henri Robin, an anti-spiritualist who used admittedly faked illusions in his “phantasmagorical” entertainments, posed for a double-exposure with a skeleton in a sheet. As the ghost makes a grab for him, Robin, wearing a cutaway and vest, his hands raised to protect himself, his face etched with over-the-top melodramatic horror, mocks the conventions of spirit photography.

The pictures from 1917 by 16-year-old Elsie Wright and her 10-year-old cousin Frances Griffiths of themselves playing with fairies behind the family home at Cottingley in Yorkshire are a hoot. The girls are lovely and the fairies have charm, but when Sir Arthur Conan Doyle came upon them and was convinced of their authenticity – and published a book saying so – the girls were afraid to admit it was just a prank done to amuse themselves. Doyle was a fierce, even aggressive, spiritualist. It was not until 1981, after enormous quantities of ink had been spilt arguing whether or not the fairies were genuine, that Frances admitted the hoax, and explained that they had drawn and painted the fairies, which were held in place with pins.

After the carnage of World War I, there was a renewed interest in spiritualism, and the photographs in the second section, Mediums, go through the 1930s. Here are pictures taken at seances both by people trying to prove they are real and by people trying to prove they are fake. Tables levitate, mediums go into trances, ectoplasm oozes from their mouths, scales are unbalanced by telekinesis, ghosts materialize – stuff like that. The anonymous picture “Levitations of the Medium Colin Evans” (1938), taken by infrared, shows him suspended above a large crowd of people, none of whom are aware of his elevation. It seems implausible, but there it is in black and white.

The last section, Fluids, deals with such phenomena as “thoughtography,” images projected onto film by mental telepathy, and auras taken by applying fingers to a photographic plate. Many of these pictures were made by scientists of one persuasion or another, and several are quite attractive as abstract images. For instance, Adrien Guebhard’s “Apposition on a Plate of Living Fingers (A, B) and Artificial Fingers, One Warm (C), and the Other (D) at Ordinary Temperature” (1897-98), consists of four cyanotypes that might pass as an example of conceptual art.

Amazingly there is nothing in the exhibition about the important work by Peter Venkman, Ray Stantz, Egon Spengler, or Winston Zeddemore, but it’s still worth a trip. After all, if something goes bump in the night, who ya gonna call?

Until December 31 (1000 Fifth Avenue at 82nd Street, 212-535-7710).