Born Lionel Lawrence Banes in 1904 in Manchester, he started his career at Gainsborough Studios in Islington in 1930, after being drawn into the film industry by his love of photography. His first film was The Hound of the Baskervilles (d. Gareth V. Gundreth, 1931) as an assistant to the camera department, loading film, pulling focus and other general duties. Progressing to camera operator, he worked on all the Cecily Courtneidge/Jack Hulbert films at Gainsborough, starting with The Ghost Train (d. Walter Forde, 1931).
During the 1940s, Banes was employed at Ealing Studios as a cinematographer on key films such as Passport to Pimlico (d. Henry Cornelius, 1949), Pool of London (d. Basil Dearden, 1949) and The Man in the White Suit (d. Alexander Mackendrick, 1951).
After Ealing, Banes went into commercial television, specialising in glossy filmed series for the likes of Harry Alan Towers and ITC, including The Adventures of the Scarlet Pimpernel (ITV, 1955-1956), The Avengers (ITV, 1961-69), The Saint (ITV, 1962-66) and Man in a Suitcase (ITV, 1967-68).