The Innocents (1961)

Starring Deborah Kerr, Peter Wyngarde, Megs Jenkins, Michael Redgrave, Martin Stephens
Directed by Jack Clayton
(actor & director credits courtesy IMDB.com)

A young woman takes a job as governess to two children at a large estate, but after witnessing ghostly visions there, fears the children have become corrupted by evil.

A faithful adaptation of Henry James' novella, The Turn Of The Screw, the picture is beautiful to look at, with vivid atmospheric scenery, and Clayton and his crew skillfully build a feeling of unease that helps escalate suspense.  Cinematographer Freddie Francis, who would later distinguish several future British horror films as their director, shows a talent for defining the visuals of the genre in eerie imagery and effectively fluid tracking shots, while still capturing the actors beautifully.  The cast is also first rate, with Stephens and Pamela Franklin beguiling as the titular children, Jenkins warm as the kindly housekeeper, and Kerr of course accomplished as the governess who may be as righteous as she thinks she is being, or possibly on the edge of losing her sanity.  I read on Wikipedia that the truth of whether Kerr's character has insight into evil or is overreacting has been much debated by scholars, so it seems appropriate that Clayton and his screenwriters, including the famed Truman Capote, have chosen to leave her character's actions for the audience to judge.  Viewers expecting a conventional ghost story with shocks and moaning spectres should be warned this isn't that type of film, but it is a beautiful production with more and more to notice upon each viewing.