Depending on the genre depends on what how the opening of a film is set out. Although all openings have the same concept, just set out differently, they set the scene, so the audience knows/ can predict what the stories about. For example if it's an animated film -ie. Disney films- they hold serenity at the beginning, its at a calm pace and its clear and peaceful, so the audience can follow and learn what this story is. Whereas a horror might leave the audience hanging a bit more, it may still set the scene- perhaps tell the audience of an evil or imply the evil is around, building up that genre from the beginning.
Why's film openings so important?
Without a film opening the audience would be lost and not know what was happening, they wouldn't really know what to predict in the following scenes. These openings are very important when creating a film because it sets the scene and tells the story, this is normally when there is a narrator, even though people barely notice, the narrator is normally present at the beginning and the end because it shows a complete circle of events.
Types of openings...
Flash backs.
Planning of landscape- set and inform where the story is set.
Narrations.
Action scene- to intrigue the audience in a fast pace scene
Chase scene- similar the the Action scene to catch the attention
My exampled of a film opening is from the women in black. Horrors are my personal favorite and believe they are very good at conveying opening to create tension and raise questions to further draw the audience into watching the rest of the film. The women in black (linked here) is a film about a small town who's children are being killed but the cause is unknown to all the adults. Throughout the opening there is a creepy tune that sounds as if it should be a nursery rhyme just slowed right down. This is the only sound throughout the opening- other than the scream from what must be the mother. The lack of speech suggests an almost hypnotic sense taking over this innocent children.
The first thing shown is a china set of tea cups and pot suggesting a play of "make believe", most horrors use children to help the portrayal of a psychological scare because they are meant to be innocent and free minded. As shown on the picture on the right, you can see an old fashion nursery room/ play room suggesting these children are families of class or wealth. This would have been set many years ago, those with class never had anything happen to them, well nothing that was revealed anyway. These children would have been left up there and known they would play without any harm. Although the music on top of this suggests otherwise.
The caring and nurturing of the dolls, the giving them drink and tucking them in the bed suggests that these girls aren't evil or horrible, they are innocent children doing what most children done. This is important when creating tension in this case for an opening because if the audience didn't know what genre this was, and there was no sound, this may have been taken very differently. However, the dark tone of the shots suggests this isn't a happy place to be, even if the children are smiling away. The darkness suggests danger, their safe play room, is no longer safe for them. This is also important when creating an opening because it suggests this happens very regularly so even the sun doesn't bother to come out as this is a forever mourning. The audience may then be lead to engage with the film and want to find out more to why these children are smiling yet the music says they shouldn't be. 
Continuing into the opening scene, the girls stop what they are doing completely and in sync look at the door then to the window. The bells in the music begin to get louder suggesting something is about to occur. The first glance of the three girls raises questions of who are they looking at, as we can't hear anything we do not know whether they are being spoken to or they being hypnotized. The way these girls are in sync creates are very creepy and eary feeling to the audience. Children don't normally do things in sync, this is abnormal and it draws in the audience.
The smashing of the china cups and dolls that were once in the hands of the innocent and caring children, are now being broken and smashed. As if the girls never cared for them. The killing of the dolls foreshadows the unsure emotion impacting on the audience because it seems they are possessed. Especially when it is shown the girls are walking over to a window, opening it as if a door. This further implies that the thing doing this to all the children doesn't physically do it themselves, but it's the children doing it. Which is very important to an opening scene as the audience is left wanting to see what is causing this and why.
The end of this scene is a pan out to show the room, in the corner shows someone in a black veil, looking at the name suggests this is the "woman in black". Yet it's important for the opening to not reveal everything, hence why this subject has their back to the camera and only half the head is shown.
