Ralph Steiner, a still photographer and cinematographer whose documentary films included the 1930's classic ''The Plow That Broke the Plains,'' died yesterday of cancer in Mary Hitchcock Hospital in Hanover, N.H. He was 87 years old and lived in Thetford Hills, Vt.
Mr. Steiner was ''a key figure in winning vanguard status for photography comparable to such painting movements as Cubism, Futurism and Constructivism and the last of the American Modernist photographers,'' said Ann Hoy, the curator of his current exhibition, ''Ralph Steiner: Seven Decades,'' at the International Center of Photography in New York.
In 1929, Mr. Steiner made ''H#2#0,'' which is considered the second American art film. With Willard Van Dyke he made ''The City'' as a documentary for the New York World's Fair of 1939. In the 1970's Mr. Steiner made a series of short films, ''The Joy of Seeing.'' Returning to still photography in the late 1970's, he produced two books, ''A Point of View,'' in the late 1970's, and ''In Pursuit of Clouds,'' in 1985.
He was the guest curator of a show opening at Dartmouth College in September, ''In Spite of Everything, Yes,'' and the exhibition's catalogue will be published as a third Steiner book.
Mr. Steiner thought of himself as a still photographer, and his wife, Caroline, said yesterday that he ''emphasized enjoyment of the visual world around him in very positive pictures.'' Although he came to the forefront in the early 1930's when sharply focused pictures of commonplace things were in vogue, he was considered to have a stylistic base in pictorialism.
Mr. Steiner is also survived by his daughter, Antonia, of New York City.
