Mills directed the ballet film "The Tales of Beatrix Potter" (1971); the film, which is without dialogue, weaves dances choreographed by Sir Frederick Ashton and performed by the members of the Royal Ballet. The film received some favourable reviews, and has been released to DVD (2004) and to Blu-ray (2011), the latter a restored version celebrating the film's 40th anniversary. Mills subsequently produced the documentary "Franco Zeffirelli: A Florentine Artist" (1973) based on the filming of Zeffirelli's "Brother Sun, Sister Moon"; the documentary was not included in the 2004 DVD release of the film.