Versatility Canon EF lens mount

the ef mount of canon eos 50



electronics of ef-s lens

its large diameter , relatively short flange focal distance of 44.0 mm allows mechanical adaptation of ef camera bodies many types of non-ef lenses. possible mount lenses using nikon f mount, olympus om, leica r , universal m42 lens mounts (among others) use of mechanical adapter without electronic control of aperture or autofocus. conversely, parfocal adaptation of ef lenses non-ef camera bodies not possible mechanical adapter not contain optical elements.

lenses earlier canon fd lens mount not usable general photography on ef or ef-s mount camera, unless adapters optical elements used because made flange focal distance of 42.0 mm. of these lenses require autofocus , aperture motors inside body isn t available in eos bodies. infinity focus lost adapter lacks optical elements. canon fd-eos adapter rare , usable fd telephoto lenses. manual connection, aperture , focus controls of lens cannot controlled or read camera; lens must focused manually. since possible metering through-the-lens, lens must manually stopped down accurately meter @ less full aperture. (this called stop-down metering.) introduction of canon eos-m mirror-less digital camera, inexpensive adapter allows full use, including infinity focusing, of fd , fl lenses.

for other lens types, adapter act extension tube, causing lens lose ability focus infinity. alternatively, lens adapters include optical elements , act weak teleconverters, possibly losing optical quality.

third-party lenses

compatible third-party lenses ef lens mount manufactured samyang, schneider, sigma, tamron, tokina, , carl zeiss. manufacturers of these lenses have reverse engineered eos electronics—except zeiss doesn t have rights use autofocus or electronic aperture control of eos cameras. use of these third-party lenses not supported canon. compatibility problems arise, no third party has access canon s specifications camera body communication. these compatibility issues occur when using newer body older third-party lens. on time, of these issues have been resolved major third-party brands.

third-party cameras

due high market penetration of ef-mount lenses, other camera manufacturers began offer ef-mount cameras. since ef-mount created slr cameras long focal flange distance, mirrorless interchangeable lens cameras can use ef lenses mechanical adaptor bridges distance.

red digital cinema company offers various camera models can equipped electronic ef-mount. many blackmagic design cameras sold in ef-mount variants.

for sony e-mount various adaptors enable using ef-mount lenses full electronic control.