When he was a child in Brooklyn, he heard a loud crash and a round object came rolling down the street toward him. When he reached for it, he saw it was a little girl's severed head, and someone yanked him away. Joel-Peter Witkin's now-famous proclivity for morbidity blossomed years later with his photos of Coney Island freak shows, and he's been art photography's incorrigible goth rocker ever since. Now in his seventies, he seems like the respectable academic he was at the University of New Mexico, but his beautifully produced photographs can be gag-inducingly gross. For instance, Man Without a Head depicts a flabby naked guy slouched in a chair as if waiting for a medical exam, but he has only a bloody stump where his head should be. Man with Dog, Mexico City is more hopeful: A view of a nude transsexual who — at least, from the waist up — resembles Frida Kahlo. Posed with her cute fox terrier, she exudes a gracious sort of charm, but the tone, while elegant, still says "freak show." Ironically, beauty and mystery are things Witkin does well when he's not being gratuitously gross. In Imperfect Thirst, New Mexico, 2016 (pictured), an old master-looking female nude wearing a barracuda on her head suggests the visionary epiphanies of a newly discovered saint thanks to the glowy northern renaissance lighting and its rapturously mystical, if surreal, Hieronymus Bosch aura. As for the fish, she wears it well, and fish do have biblical resonance. Beauty also is a theme in Anna Akhmatova, Paris, France, a still-life tableau with an armless miniature statue of Venus, some grapes, flowers and a clock ensconced in someone's well-formed fingers that are, unfortunately, attached to a severed arm. Witkin is great at what he does, but in an age when the freaky shock-jock excesses of Quentin Tarantino's movies and Donald Trump's tweets have inspired national revulsion, his timing may be less than ideal.