2. Professional cinema standard formats

Traditional or professional cinema, as we know it today, has been developed since the birth of the cinematograph. It is based on internationally established principles and standards. The term "format" can refer to both :

• the type of film, considered solely from the point of view of its geometric characteristics. The format is used to differentiate the various types of film by their width, shape and perforation spacing. Here, format is defined by film width, expressed in millimeters;

• the ratio of image dimensions on the screen: for example, 1.65 × 1, usually abbreviated to 1.65 (pronounced "one sixty-five"), means that the image on the screen is 1.65 times wider than it is high.