As well as stage presentations, in recent years there have been a number of film adaptations, including Macbeth by Roman Polanski (1971) and Throne of Blood by Akiro Kurosawa (1957). Despite the play's bold outline, there are specific difficulties which any director must confront. The first of these is the role and staging of the supernatural elements of the play, specifically the Witches, the dagger, and Banquo's ghost.
The Witches are a vital component of the play because their prophecies in Act I, Scene 3 and Act IV, Scene 1 provide Macbeth with motivation for his actions. Banquo gives a hint as to their appearance when he refers to their chapped fingers, skinny lips, and beards; they need not, however, be costumed in the traditional form of the Halloween hag. They must have the capability of vanishing. Complex stage machinery in the Elizabethan theatre could have allowed them to "fly," but this is not necessary, because vanishing tricks can be performed in other ways, particularly by using a gauze curtain, which can be transparent or opaque depending on how it is lit. As an alternative, modern productions might also make use of visual projection or the voice-over.
The fact that the ghost of Banquo in Act III, Scene 4 has no lines means that it is frequently played in modern productions as simply a lighting effect, perhaps accompanied by a rushing of wind. This treatment reinforces Lady Macbeth's incredulity at her husband's reaction. She compares her husband's belief in Banquo's ghost with his faith in the earlier apparition of an "air-drawn dagger." A question therefore arises: Should all such effects be played invisibly to the audience?
