The film version of To Kill a Mockingbird is one of the better examples of a successful transition from novel to cinema. It's hard to overlook the movie's achievements: Gregory Peck won the Oscar and Golden Globe for Best Actor; the film was nominated for Best Movie; and Mary Badham (Scout) became the youngest actress to be nominated for Best Supporting Actress. Peck's performance is generally considered one of the best in the history of film.
Naturally, it is impossible to tell the entire story of a 250+ page novel in a two hour movie, and the film version of TKAM sadly was forced to leave out many interesting characters (Aunt Alexandra, Uncle Jack, Dolphus Raymond, Miss Caroline) as well as some key scenes (Scout's school days were eliminated completely, the missionary tea, Calpurnia's church). However, the storyline remains intact and the powerful courtroom scenes of the Tom Robinson trial are terrific. Brock Peters is superb as Tom, and James Anderson is absolutely chilling as Bob Ewell. Jem and Scout's end of innocence is documented in several different ways, and the Boo Radley storyline is maintained throughout. Robert Duvall's film debut as Boo is one of the movie's highlights. The use of black-and-white film gives the 1961 film a purposely dated look, and I have always found it a perfectly acceptable choice. All in all, the film version is excellent and does the novel justice. It is also pertinent that no other movie version of TKAM has ever been considered--a further tribute to the quality Alan J. Pakula production.