In general, in order to use a copyright work you need to get permission from the copyright owners. This process can be especially long and expensive when dealing with films, since they are complex works involving copyrights of a large number of contributors (music, script, cinematography, etc.). You can find more information about this here.
In some cases and under certain conditions, you are allowed to use protected works without the need to get permission. These cases are known as copyright exceptions and are part of the on-going UK copyright reform. The UK Copyright Act currently provides some exceptions, such as quotation, news reporting, education, research and private study, archiving and preservation.
It is not necessary to ask permission to use public domain films, since their copyright has expired. However, due to the long copyright duration, there are only a few films in the public domain and even though a film may be out of copyright, some of its elements – like literary characters – may remain protected under different intellectual property law, particularly trade mark. You can find more information about the public domain here.
Copyright law around the world is based on a simple premise- surrounding the planet earth there is a cloud of spirituality, of ideas. Any two people at the same time can pull down the same idea. And ideas are free.
What is copyrightable is the expression of the idea, be it as a poem, sculpture, libretto, novel or script. Sometimes, the difference between what is an expression of an idea and what is an idea can become complicated. Lawyers love the billings they make for cases such as this.
Basically, two screenwriters can come up with the same storyline for a movie. They write two very different screenplays, but the storyline idea (which cannot be copyright protected) cannot be disputed. I have taught enough screenwriters in enough countries to know that if you are reading this, you are getting pretty paranoid by now. Please force yourself to finish reading this chapter, so you can develop a positive mental attitude towards copyright.
Many writers and artists labour under the misconception that they must fill out an official form, and write the letter ‘©’ in order to assert their claim for ownership of the copyright. In fact, all countries recognize that the artist owns copyright from the moment it is created.