The standard gauge since the turn of the century.
The standard gauge of 35 mm film is as old as the film industry itself, having been used in Dickson's original Kinetoscope of 1891. This width of film, with four perforations per frame, was adopted as an international standard in 1909 and has remained largely unchanged ever since.
While videotapes have become progressively narrower, but maintaining the image resolution, the 35 mm film format has remained unchanged. Improvements in technology have instead allowed film resolution and emulsion speed to increase.
The perforations, at one time round, were modified so as to have flat leading and training edges. Register pins in camera gates are machined to make a ...