A film slitter, sometimes also called film splitter, is a device used in subminiature photography to slit 135 or 120 roll film into 16mm film or Minox film for use in subminiature cameras.^{[1] [2]}

The earliest film slitter was made in the 1950s by Suzuki Optical Works in Japan for use with their Echo-8 subminiature camera. This film slitter consists of a roller cutter which slits a strip of double-perforated 16mm film in half, into two strips of perforated 8mm film for Echo-8 camera^[3]

One type of film slitter uses three sharp blades in a block fixture to cut 35mm or 120 roll film into subminiature film.

Another type of slitter uses a roller cutter to cut 35mm film into two strips of Minox film or one strip of Minox film plus one strip of 16mm film^[4]