A documentary film is produced in much the same way as a regular movie. A documentary is a short film; and will usually cover a single subject or phenomenon like the recent movie Al Gore documentary on the environment 'An inconvenient Truth'. Documentaries do also pass true movie review process and this can favour or not how well received it will be by the public. If you would like to know more about a certain documentary you can check it out in an internet movie database and read more about it before going out to borrow or buy it. Most cover subjects that is factual from events that have happened or are happening. Anything in the social, political or environmental can be the subject of a documentary. Since there are no cameras at the very time the event takes place a story line is created from reports of the event and actors then re-enact the story. This does not come cheap. To produce even a modest budget documentary you will need to be in good terms with your bank manager and get a letter of credit to pay for all the stuff you will need. Can you imagine thirty years ago it was 50 cent for two movies!