The lenses are classified:
EF lenses, corresponding to Canon DSLR , full frame residuals can be mounted.
EF-S lenses, corresponding to residual frame DSLRs only, full frame not available.
EF-M, corresponds to EOSM mirrorless (residual frame).
RF, corresponds to EOSR mirrorless (full frame only for now).
Canon, a Japan-based integrated group of world-leading producers of imaging and information products, has globalized and expanded its business into a wide range of fields over the years since its founding in 1937.
Canon's product lineup*** is spread across three main areas: personal products, office equipment and industrial equipment, with major products including cameras and lenses, digital cameras, printers, copiers, fax machines, scanners, broadcasting equipment, medical equipment and semiconductor production equipment.
Canon is headquartered in Tokyo, Japan, and has four regional sales headquarters in the Americas, Europe, Asia and Japan, with 200 subsidiaries and over 100,000 employees worldwide.
History:
On March 9, 2016, Japan's Toshiba Corporation held a board of directors meeting and finally decided to sell its Toshiba Medical Systems Corporation to Canon, which made a purchase offer of 700 billion yen (about 40.5 billion yuan).
On September 5, 2018, Canon officially announced the EOS R system, EOS R full-frame dedicated micro and RF lenses.