The 'Mean Girls' film poster is targeted at teenage females. This is apparent by the excessive use of the colour pink, as this is a stereotypical 'girly' colour. It also follows the conventions of a film poster as it has a large, bold title, names of the main cast members and director'producer credits. It also has a memorable slogan and displays the release date.
The film poster for 'The Shining' follows typical conventions of a horror film as it contains scary and critical stills from the film and also has a vold, black title that is memorable. There is also a slogan that also advertises the film, as well as promoting the terror of it to attract its target audience of thrill-seekers. As well as this, it also contains cast names, directors and producers and the release date.
The film poster for 'The Dark Knight Rises' is aimed at young people and adults. This is depicted by the use of dark colours that wouldn't attract the attention of children. It contains the lead actor as the sole image in the poster, in an image that looks as if it could have been lifted from a frame. It also has the conventional features of a film poster. as the posters above do.
'The Little Mermain' is a Disney classic aimed at young children, mostly girls. The fact that the film is animated already tells us that the target audience is children, but the image of a mermaid will attract young girls as girls dream of being mermaids and princesses, so the image will make them want to see the film. The soft blue colour also entices young children in to want to see the film. Along with these features it also follows the typical conventions of a film poster. It also clearly displays the film company as it is a well-known company and they will gain audience members on brand-awareness alone.
The 'Jurassic Park' film poster doesn't follow the convention of having the main character/cast member on the poster. This is because the film centres around dinosaurs and there is no real 'main' character as the film focuses on the dinosaur. However this has worked to the producers advantage as the silhoutted image on the dinosaur has become iconic. This film poster is fairly minimalistic as it has a plain black background and white writing which stand out. It then shows the credits of actors etc, but not very clearly in dark grey writing.
This film poster for the blockbuster 'Avatar' only follows a few conventions of a typical film poster. It has one of the main characters displayed on the front and the title. However it does not include any names of actors/producers and the director. It also does not say the release date. This could be to not distract attention away from the picture and the title.
-KW
In this poster, the only image is of McMurphy (Jack Nicholsen, the main character) looking up. This doesn't seem to give much, if anything away about the story or the ending. This could intrigue audiences as they don't know much about the film at all. However, the creators of the film have placed a couple of clues in there to indicate elements of the story. The character is standing in front of a wire fence, typically used in institutuins where you're not allowed out. He is also staring up at a broken padlock, which could imply an escape. Of course, anyone who has seen the film knows its about Nicholsen's character being sent to a mental institution for sexual abuse, and he plans an escape. The film poster doesn't give any of this away to begin with, but once you know the story it becomes fairly obvious. This is the type of effect I'd like to create with my poster. 
Some film posters can give a little too much away however. The famous poster 'Jaws' is a very good film poster as far as contruction goes, but the image chosen may give the story away to some extent. The image is of a large skark about to catch a swimming girl in a bikini. It may not give away the ending, but it does however pretty much say what happens. The writing is also in blood red, which could itself be a hint to the story. The poster does still leave the audience guessing as they do not know the circumstances to the shark attack, they do not know any of the characters (other than the shark) and they are unaware of the ending. So it is quite clever the way they have done it. 
Film posters be used to advertise films, but they have become a pop culture phenomenon in recent years and some have become iconic, appearing on merchandise, T Shirts, album covers and posters on bedroom walls.
