ANSI/I3A IT2.21-1994
This lnternatlonal Standard specifies the method fordetermlnlng the IS0 speed of colour reversal camerafilms producrng continuous-tone prctorial images thatare intended to be viewed on transparency tllumlnatorsor by prelection as slrdes It also applies to8 mm and 16 mm motion-picture films used in nonprofesslonalapplications.This International Standard does not apply to professionalmotion-picture films used in non-professional applications.