The Canon EF-M lens mount, introduced in 2012, was a derivative of the

Canon EF lens mount The EF lens mount is the standard lens mount on the Canon EOS family of SLR film and digital cameras. EF stands for "Electro-Focus": automatic focusing on EF lenses is handled by a dedicated electric motor built into the lens. Mechanically, it i ...

designed for use with the

Canon EOS M Canon EOS M is the first mirrorless interchangeable-lens camera produced by Canon. DPReview noted that the EOS M is effectively a miniature version of the Canon EOS 650D, which was introduced in June 2012, with a simpler physical interface. The ...

mirrorless interchangeable-lens camera A mirrorless camera (sometimes referred to as a mirrorless interchangeable-lens camera (MILC) or digital single-lens mirrorless (DSLM)) is a digital camera which, in contrast to DSLRs, does not use a mirror in order to ensure that the image ...

. The EF-M lens mount is one of Canon's two systems for mirrorless cameras, the other being the RF mount. The M system has an 18 mm

flange focal distance For an interchangeable lens camera, the flange focal distance (FFD) (also known as the flange-to-film distance, flange focal depth, flange back distance (FBD), flange focal length (FFL), back focus or register, depending on the usage and source ...

(compared to 20 mm for RF and 44 mm for EF and EF-S) and a 47 mm throat diameter (compared to 54 mm for EF, EF-S, and RF). As it is designed for use with an

APS-C Advanced Photo System type-C (APS-C) is an image sensor format approximately equivalent in size to the Advanced Photo System film negative in its C ("Classic") format, of 25.1×16.7 mm, an aspect ratio of 3:2 and Ø 30.15 mm field d ...

-sized

image sensor An image sensor or imager is a sensor that detects and conveys information used to form an image. It does so by converting the variable attenuation of light waves (as they refraction, pass through or reflection (physics), reflect off objects) into s ...

, it features the same

crop factor In digital photography, the crop factor, format factor, or focal length multiplier of an image sensor format is the ratio of the dimensions of a camera's imaging area compared to a reference format; most often, this term is applied to digital ...

(of roughly 1.6) as the existing EF-S lens mount. The M system was somewhat limited as Canon had only released 8 native lenses, listed below. There was a lack of native lenses with a large aperture, the exceptions being 22 mm 2.0 and 32 mm 1.4. In 2014, third party manufacturers started to present their M lenses. In addition, it is possible to use Canon EF and EF-S lenses (made for the Canon DSLRs) with an adapter. This solution reportedly works well also with regard to the autofocus, but it takes away the size advantage of the smaller M system. Suitable adapters (from EF to M or from EF-S to M) are made by Canon as well as third party manufacturers. As is common with mirrorless systems, the adapter solution is not backwards-compatible with Canon's DSLR cameras: this means that you cannot put M lenses on a DSLR. The EOS EF-M system was officially discontinued in October 2023. Although, Canon hadn't released any new cameras or lenses for a number of years pior to the discontinuation.

Compatibility

List of EF-M lenses from Canon

List of EF-M lenses from 3rd-party (AF only)

Images

References