But while Mr. Stuart's documentaries won acclaim and cemented his reputation, he won a special sort of following with the 1971 musical fantasy Willy Wonka.
That film was his response to a young reader of the Roald Dahl children's classic Charlie and the Chocolate Factory: Madeline Stuart asked her father to make a movie of the book she loved.
A collaborator on Willy Wonka was screenwriter David Seltzer, who at 26 had gotten his first job in the film business - making documentaries - from Mr. Stuart and calls him "a mentor by way of drill sergeant, much-feared boss, and much-loved friend."
During the 1960s and 1970s, Mr. Stuart was associated with David L. Wolper, with whom he established a base of West Coast documentary production at a time when New York filmmakers and TV networks' news divisions dominated the field.
By 1980, Mr. Stuart was an independent producer and director whose credits include portraits for PBS's American Masters on artist Man Ray and the director Billy Wilder. He was executive producer of the 1980s ABC series Ripley's Believe It or Not, whose host was Jack Palance.
Airing on PBS in 2005, The Hobart Shakespeareans was Mr. Stuart's profile of a teacher in inner-city Los Angeles whose fifth-grade class each year performed a play by William Shakespeare.
He produced or directed various dramas including the 1981 TV film Bill, starring Mickey Rooney and Dennis Quaid, which won a Golden Globe and a Peabody award.
Besides his daughter, Mr. Stuart is survived by sons Andrew and Peter.