Mawu a M'munsi

a ISO ndichidule cha International Standards Organization; ASA, ndichidule cha American Standards Association. Kumbali zina za Yuropu, DIN (Deutsche Industrie Norm) imagwiritsiridwanso ntchito. Filimu yolembedwa ISO 100/21 ndiyo ASA 100, kapena 21 DIN.