mm is the unit used to measure film size. It stands for millimeter.
The standard film size is 35 mm. The standard frame size of a still camera film was 24 x 36 mm.
mm is the smallest unit to measure length of an object. It is followed by cm then in and so on.
1 cm = 10 mm
1 in = 2.54 cm
1 in = 25.4 mm
