positive: a film showing a photographic image whose tones correspond to those of the original subject
film: photographic material consisting of a base of celluloid covered with a photographic emulsion; used to make negatives or transparencies
manichaeism: a religion founded by Manes in the third century; a synthesis of Zoroastrian dualism between light and dark and Babylonian folklore and Buddhist ethics and superficial elements of Christianity; spread widely in the Roman Empire but had largely died out by 1000