i) Usually in an opening sequence there is an important incident. This could be a murder (Se7en), an escape (Mission: Impossible) or something being stolen. This incident will be the catalyst that sends the protagonist on their journey.There can also be the build up to an important event, such as in Legally Blonde.
Usually the protagonist or the villain are revealed to the audience in the opening sequence and so this will set the scene for the film ahead along with the event/s that take place.
ii) The opening sequence sets the scene for the film. This could be done by showing the main characters and through their actions and personality the audinece can see what will happen.
They also demonstrate to the audience what normal life (or equilibrium) is like before the disruption that happens in the film. This disruption may also take place in the opening sequence but doesn’t always. Often in films such as James Bond the event in the opening sequence is somehow linked to the main story, but this may not be revealed to the audience straight away. This helps build suspense.
iii) The audience is able to see the equilibrium in the film. By doing this they can see the contrast once the disruption occurs. Using Barthes’ theory (the enigma code), means that early mysteries are shown which will link to the ending of the film and so set up a surprise or twist for the audience.
iv) The makers of the film use opening sequences to show where and when the film will take place and therefore satisfying audience expectations of the film. They also use it so they can put in any extra information before the main plot begins that may be useful throughut the remainder of the fil and will probably tie in somehow.