— the most modest matrix format found in cameras with interchangeable lenses; is used in devices with Four Thirds (4/3) and Micro 4/3 mounts from different manufacturers, and therefore lenses for them are often designed for several systems. The size of such a matrix is 18x13.5 mm, which diagonally gives approximately 4/3 of the conditional "Vidicon" inch, which is 17 mm (hence the name).
