The depth of field is used in film to focus on a certain character or object whilst blurring out the enviroment or other characters in the scene. This helps the audience focus on a specific thing in the scene whilst also being aware of the enviroment or other characters in the backround. it is also ofte used to capture character key emotions in scenes which often changes the mood of the scene or helps us to empathise with characters.

Shallow focus- used to give a blurred effect whilst still being able to identify the environment or background. often used to put emphasis on a specific thing in the scene to attract the audience to it.

Deep focus- used to show everything going on in the scene. often showing a busy environment or used when lots of things are happening to show that its a busy environment. it can also be used to capture lots of reactions or different points of views in the scene.