Compare the film version and the text.

There have been several film versions of Othello. Three are notable.
The first starred Orson Welles, who also produced and directed the film in 1951. The movie is very much of its era, filmed in the film noir tradition, which was a genre marked by its fatalism and air of menace. Scenes are characterized by strong contrasts of light and dark and the casting of long shadows, particularly around the character—usually the protagonist—who is doomed. Welles used these elements to convey Othello's fatal demise.
In the following decade, Laurence Olivier starred in a film version in 1965 that was based on his stage performance. This version, for which he had his entire body covered in dark brown make-up and spent much of the film grinning like a minstrel character, is not regarded well today due to its use of blackface. One is so distracted by Olivier's performance of a black man that the details of the play become less important.
The best-known contemporary version of Othello that adheres to the original play is the 1995 version directed by Kenneth Branagh, starring Laurence Fishburne. This version is different from the play and from previous film versions in that it emphasizes sexuality. However, it does a better job of depicting Othello's slow descent into jealous rage as a result of Iago's instigations.
Iago, played by Branagh, posseses a visceral hatred of Othello. At one point, he looks directly at the camera and, in a statement dripping with venom, states, "I hate the Moor." In the play, this line occurs in act 2, scene 1. It is here that Iago, in his asides to the audience, makes his villainous intent clear. He manipulates Roderigo, who is in love with Desdemona. 
The play reveals the inconsistency of Iago's feelings toward Othello. He is, in one moment, propelled by resentment, for Othello appointed Michael Cassio to be his lieutenant, though Iago believed that he would have the position. In another moment, he files his resentment of Othello under anger over being cuckolded, though he does not know for sure if it occurre—no matter, the rumor is enough to lead him to seek revenge. Branagh's film makes Iago's hatred more clearly about sexual envy and resentment over Othello's interracial union with Desdemona. Ads for the film show Fishburne and Irene Jacob (Desdemona) in a loving embrace, while Branagh lurks in the background like an evil ghost.