Most of the time the marketing team from a studio talks with the director and producer on how they want to promote the movie... scene's and shots are chosen and they then devise a narration based on selected scenes and chose the music, graphics and voice-over... and some low level kid edits it all together...Some marketingteams are really good.. and they can really sell bad movies with a 30 sec trailer..
there are expection of course with movies having scenes and stuff in the trailer without appearing in the actually movie.. like Psycho, Terminator 2 and Spiderman.. in those trailer there is a more involvment from a director and producer themself..







Face the future.. Gamecenter ID: nikkom_nl (oh no he didn't!!)







