A size of photographic film in which the image produced on the negative is in the approximate size range 6 × 4.5 cm to 6 × 9 cm; frequently attributive, designating photography or cameras using this type of film.
Origin
1970s.
Definition of medium format in US English:
medium format
noun
Photography
A size of photographic film in which the image produced on the negative is in the approximate size range 6 × 4.5 cm to 6 × 9 cm; frequently attributive, designating photography or cameras using this type of film.