What makes an effective opening?

It's actually very simple to make the opening of a movie effective for the audience.  The best opening of a film, , MUST engage the audience.  We have to be engaged by what we are seeing and feel the need to carry on watching the film. if the opening of the film does not grab the viewer s attention or at least meet their expectations they will simply not want to watch it.

"There's no one answer as far as how to do that.  The key is to figure out what not to do first.  Don't spend the first 10 pages of the script giving us exposition, introducing your characters, setting up moods/themes, etc.   Because you've lost us already by page 10 or whatever.  Novice writers show their hand too early.  We're forced to learn the whole back story (or a great portion of it) of characters in the first act, rather than the writer allowing any type of discovery.Engage us.  Shock us.  Make us laugh.  Introduce that character briefly, with a couple quick broad strokes, and then throw them into the pit right away and let us see how they claw their way out.   " ( Producer,screenwriter, former Sony Pictures script reader/story analyst,)

The film needs to show glimpses of what genre it is at the start, this also makes it a good opening. For example the opening scene of a comedy genred film should be halairous, this would grab the viewers attention and make them want to watch the rest of the film. this will make them think the rest of the film will be funny.People watching a thrilling horror want the film to be scary therefore the opening scene must be terrifying.

Most opening scenes to a horror film have very little dialogue some have no dialogue at all because they include just one character who is isolated and alone. Horror films always seem to open with alot of strange diegetic and non-diegetic sound. Alot of the sounds that are added are for the purpose of building suspense, some of these suspense building sound effects are terrifying and unexplainable. In the opening of most Horrors something very dramatic usually happens that gets the viewers exited and makes their hearts beat out their chests. this is the kind of effect that i would like to achive.