Sid Laverents, who started making movies in his Southern California basement after he turned 50 and became perhaps the most celebrated hobbyist in the amateur film world, his resourceful and dryly giddy work chosen for the National Film Registry, died on May 6 in Chula Vista, Calif. He was 100 and lived in Bonita, Calif., near San Diego.

The cause was pneumonia, said his wife, Charlotte.

Mr. Laverents was a jack of many trades, a perpetual self-inventor. He played a dozen instruments and supported himself through the Depression as a vaudevillian one-man band; he was also a sheet metal worker who helped build World War II airplanes, a self-published writer, a Fuller Brush salesman, a sign painter, a carpenter and an aircraft engineer.

But he was best known for the more than 20 movies he made from 1959 until his death, as a member of the San Diego Amateur Moviemakers Club. They included nature films ( one about snails, filmed in his backyard), goofy comedies ( “It Sudses and Sudses and Sudses,” a “Sorcerer’s Apprentice”-like tale about canisters of shaving cream run amok in the bathroom) and deadpan autobiographical stories, including “The Sid Saga,” a four-part look at his own life, completed in his 80s.

Mr. Laverents had long been known to cineastes, members of amateur film clubs and other connoisseurs of noncommercial filmmaking, but in 2000, at 92, he got wider recognition after his “Multiple SIDosis” was included in the National Film Registry, a list of movies selected for preservation in the Library of Congress by the National Film Preservation Board. It is one of a handful of amateur works so designated, including the Zapruder film of the Kennedy assassination.