Canon Lens format abbreviation - the only difference between Canon EF and EF-S lenses is that the latter has been designed for Canon digital cameras with APS-C sensors, such as the Canon EOS 700D. Canon EF-S lenses should not (and in most cases can not) be mounted on Canon EOS film and digital full-frame cameras with 36x24mm sized sensors because of the larger mirror used in these cameras. If mounted, damaged to the mirror may be caused upon shutter actuation it would hit the lens rear element. EF-S lenses feature a protective pin that stops these lenses from being mounted on a full-frame EOS camera.
Standard lens system for EOS cameras since 1987. A large-diameter fully electronic lens mount, transferring data between lens and camera. There are more than 60 Canon EF lens models.