Professor Hans Holzer carefully examines historic photographic evidence of ghosts and paranormal activity, explaining which images contain convincing proof and which may be trickery For more than a century, psychic researchers have amassed a body of photographic evidence of the afterlife. Indeed, according to professor Hans Holzer, photography gives us one of the greatest tools in documenting souls that continue to exist among us after death. Here Holzer looks at the evidence of ghosts revealing themselves to us on film, and shares examples of psychic photographs, many of which were taken during séances.