The ASA (as for American Standards Association) photographic exposure system, originally defined in ASA Z38.2.1 (since 1943) and ASA PH2.5 (since 1954), together with the DIN system (DIN 4512 since 1934), became the basis for the ISO system (since 1974), currently used worldwide (ISO 6, ISO 2240, ISO 5800, ISO 12232).
ðɪ ˌeɪˌɛsˈeɪ æz fɔːɹ ɐmˈɛɹɪkən stˈændɚdz ɐsˌoʊsɪˈeɪʃən fˌoʊɾəɡɹˈæfɪk ɛkspˈoʊʒɚ sˈɪstəm, ɚɹˈɪdʒɪnəli dᵻfˈaɪnd ɪn ˌeɪˌɛsˈeɪ zˈiː θˈɜːɾi ˈeɪt.tˈuː.wˈʌn sˈɪns nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi θɹˈiː ænd ˌeɪˌɛsˈeɪ pˌiːˈeɪtʃ tˈuː.fˈaɪv sˈɪns nˈaɪntiːnhˈʌndɹɪd fˈɪfti fˈoːɹ, təɡˌɛðɚ wɪððə dˌiːˌaɪˈɛn sˈɪstəm dˌiːˌaɪˈɛn fˈoːɹ θˈaʊzənd fˈaɪvhˈʌndɹɪd twˈɛlv sˈɪns nˈaɪntiːnhˈʌndɹɪd θˈɜːɾi fˈoːɹ, bɪkˌeɪm ðə bˈeɪsɪs fɚðɪ ˌaɪˌɛsˈoʊ sˈɪstəm sˈɪns nˈaɪntiːnhˈʌndɹɪd sˈɛvənti fˈoːɹ, kˈɜːɹəntli jˈuːzd wˈɜːldwaɪd ˌaɪˌɛsˈoʊ sˈɪks, ˈaɪzoʊ tˈuː θˈaʊzənd tˈuːhˈʌndɹɪd fˈoːɹɾi, ˈaɪzoʊ fˈaɪv θˈaʊzənd ˈeɪthˈʌndɹɪd, ˈaɪzoʊ twˈɛlv θˈaʊzənd tˈuːhˈʌndɹɪd θˈɜːɾi tˈuː.