Large format photography refers to any imaging format of 9 cm × 12 cm or larger. Large format is larger than "medium format", the 6 cm × 6 cm or 6 cm × 9 cm size of Hasselblad, Mamiya, Rollei, Kowa, and Pentax cameras, and much larger than the 24 mm × 36 mm frame of 35 mm format.
Old studio camera
Lens and mounting of a large format camera
Scheimpflug principle
Ansel Adams's large format photograph The Tetons and the Snake River (1942)
Medium format has traditionally referred to a film format in photography and the related cameras and equipment that use film. Nowadays, the term applies to film and digital cameras that record images on media larger than the 24 mm × 36 mm used in 35 mm photography, but smaller than 4 in × 5 in.
Popular examples of medium format film cameras
A size comparison of medium-format film (left) and 35 mm film. Medium-format film lacks the sprocket holes of 35 mm film.
Pentax 6×7 format SLR camera with perspective control lens
50th anniversary Hasselblad 500 CM classic camera kit