Conventions of an opening sequence

In opening sequences, the audience need to be enticed and want to carry on watching the rest of the film. If this doesn't occur within the first couple of minutes of the opening sequence then the audience will just tune out and want to stop watching. Also an opening sequence should give some information about the film, but at the same time shouldn't give away too much so that the story can't progress much further; the opening sequence could be effective if clues leading towards the rest of the film are given. Furthermore, in an opening sequence all of the titles should appear in these first 2-3 minutes in order to get all of this information across and out the way; these people need to be recognized for their work and this is the way to do it. They should include titles about who is starring in it, the distributors, company names involved, who directed/produced it, music by etc. These should be done in an interesting way so that the audience doesn't get too bored by the opening section.