Most of us are now quite used to reading plays. However, any study of the play  on the page that does not take into account an imaginative construction of how that play might appear  on the stage will be not a complete study of the play. It is true also with the study of a film script. We may have more instructions to help us visualise the script as it would appear on film, but that imaginative leap still must be made. When we view the film, we are in a good position to determine whether it is true to what we see as the writer's intentions, or whether we might not have interpreted some of it differently. We are in a position to judge the success, or otherwise, of the choice of visual images to support the ideas the scriptwriter wishes to convey.

How does a film script differ from the text of a play?

Both a film and a play communicate by visual as well as verbal means, but the writer of a film script has the ability to indicate far more visual means of communication than does the writer of a play. The playwright must create a world in the minds of the audience through the exchanges between the characters. The principal difference between a play and a film script is that the play script is a much more complete work. Essentially a theatre director realises the written play text. He may drop a scene, edit lines, create a visual trick to overcome a missing moment in the text, but the basic task is to realise the written word on a stage. A film scriptwriter's task is to provide a blueprint for the work of the director, the cinematographer, the designer, the composer, the sound designer, the actors.

Both the playwright and the film scriptwriter contribute their creative vision, sometimes called 'the world' of the play or film, but the theatre director  interprets the play, whereas the film crew  build upon the film script. Another difference is that film is a more visual medium in that the camera interprets what the audience sees. On the stage, we watch the whole play unfold. A moment may be highlighted by a sound effect or lighting change, but this cannot compare to the detail the camera can reveal. For example: a play text calls for the character of an old lady. Her characteristic is 'frailty' and the actor acts 'frailty' on stage. A film script calls for the same characteristic, but the writer sees her ancient arthritic hands as significant. It is not for the script writer to do the director's work by calling for a close-up shot of her hands, but the writer might open the scene with 'Her old hand struggled to remove the lid of the biscuit tin...' There are, therefore, two versions of a film set down in writing: the  pre-production script  prepared by the scriptwriter through various stages or drafts, in consultation with the producer and director. This finally becomes the shooting script for the film. After the film has been shot, edited and the final cut approved by the director and producer, a  post-production script is drawn up by the production company. This post-production script is a written record of the film and contains the timings for each scene, the transcript of the dialogue spoken in the film and terse descriptions of the action taking place in each scene.

The script of  The Sum of Us opens with a scene from the past. That it is a scene from the past is immediately obvious from the use of black and white photography, a  filmic convention that most audiences would understand as signifying the past. This is further reinforced by the use of the  voice over, another convention that we are used to in film, but which might seem strained in a stage production. The change to colour clearly indicates a return to the present but the reader/audience is now ready to accept any part of the script designated as 'B&W footage' as belonging to the past. Any narrative provides for its readers/audience an  orientation, an introduction to the main characters, the setting and the time. A film script has the advantage of presenting a visual orientation during the course of the opening titles. This is a convention that has become widely used since the 1960s. Although the script of  The Sum of Us uses the running of the titles to help set the scene, it goes further, communicating certain information to the reader/audience even before the titles begin, by verbal as well as visual means. Because of the conventions of film, however, we realise that this is all part of the orientation.

What information have we gleaned before the titles have finished running and the film proper can be said to have begun?

1. This is probably going to be a script about families, a gentle film, perhaps even about love;
2. It is set in a harbourside, but unpretentious suburb (note the neighbour with greyhounds, the local pub);
3. The main character is a young man who, the script tells us, is called Jeff and is twenty-four
4. A second character is his dad (the script tells us this, but the film shows them entering the same house)
5. Dad is interested in finding a partner. Thus the script's orientation gives a  narrative image for the whole film.

Narrative image refers to the expectation of the reader/viewer as to the type of narrative to expect. A film script's orientation differs from that of a play in that it can be presented at the same time as information is being presented through the titles, before the serious action begins. A play script needs to be more economical in its orientation.  (For an explanation of narrative image, see McMahon and Quinn:  Real Images: Film and Television. Macmillan, South Melbourne, 1986.)