This International Standard specifies the dimensions of the camera aperture images and the relative positions of the vertical and horizontal centrelines of the intended image area with respect to the reference edge and the perforations of the camera negative film for 35 mm motion-picture cameras. 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.