Motion-picture cameras used for different purposes require different aperture sizes. This International Standard specifies the image dimensions resulting from four styles of apertures used for the following purposes.
Style A: Four perforations per frame nonanamorphic sound motion pictures.
Style B: Four perforations per frame anamorphic sound motion pictures.
Style C: Four perforations per frame instrumentation photography and full-frame motion pictures.
Style D: Three perforations per frame motion pictures.
This International Standard also specifies the position of the photographic emulsion and the frame rate for 35 mm motion-picture cameras.