Complex sentence: He began as a camera operator working on Eastwood's films of the late 1960s including Coogan's Bluff and Two Mules for Sister Sara, becoming a main cinematographer in 1971 in The Beguiled in which he worked as director of photography.
Split into simpler sentences: He began as a camera operator working on Eastwood's films during the late 1960s, his credits including Coogan's Bluff and Two Mules for Sister Sara. He became a main cinematographer in 1971 with The Beguiled in which he worked as director of photography.