WHY ARE OPENING SCENES IN MOVIES IMPORTANT?
In movies the opening scene is usually very important for several different reasons. Drawing in the audience is very important and often first impressions are key when it comes films. Its important to draw the audience in from the start so they entertained throughout. There are several movies that achieve this for example the Dark Knight Rises achieves this perfectly. The opening scene to the film involves an action packed bank robbery, the scene immediately grabs the attention of the audience.
Another reason the opening of a movie is important is setting the tone for the movie, straight from the go the audience need to know what type of movie it is. Its important to capture the theme of the movie in the opening minutes of the movie. This is so the movie seems consistent and the audience know what there walking into. Its also important to show what genre the film is from the start as well, an action movie would usually start of with a scene...well action packed! A perfect example of a movie which shows what type of movie is from the start is, Saving Private Ryan. The action/war drama from the starts with an action packed, realistic scene where American troops storm Omaha beach. The scene is very graphic and it captures what seems a very realistic depiction of what the battle and war was like.
Its also key that the opening scene of a movie introduces characters and the setting this can be done in various ways. Also its important that the movie that the cast is introduced this is usually done through title sequences (see below for examples) which sometimes can tie in with introducing characters as well as actors and cast.
These are a few important reasons to help you understand why its so important for a movie to have a good opening, for more detail look at some of the examples below.