Audiovisual introductions in 1839

thumb|Daguerreotype portrait of a daguerreotypist displaying daguerreotypes and cases pictured in an airtight frame, 1845 thumb|upright=1.1|Daguerreotype of Louis Daguerre in 1844 by Jean-Baptiste Sabatier-Blot

thumb|Digital scanning of microfilm

thumb|A 1 mm diameter microphotograph,