Taken by a New Orleans figure painter more than three decades ago, these photographs of bare-chested or nude black men may have inspired some of Robert Mapplethorpe’s most memorable and starkly erotic images. But this long overdue New York debut shows that Mr. Dureau granted his subjects an individuality, vulnerability and intensely personal gravity that Mapplethorpe’s more objectified models often lacked. They are portraits in the truest sense and wonderfully immediate and alive.