Canon EF-M lens mount explained

Mount Name:	Canon M mount
Type:	bayonet
Inner Diameter:	47 mm
Flange:	18 mm

The Canon EF-M lens mount, introduced in 2012, is a derivative of the Canon EF lens mount designed for use with the Canon EOS M mirrorless interchangeable-lens camera. The EF-M lens mount is one of Canon's two new systems for mirrorless cameras, the other being the RF mount.

The M system has an 18 mm flange focal distance (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-sized image sensor, it features the same crop factor (of roughly 1.6) as the existing EF-S lens mount.

The M system is somewhat limited as Canon has issued relatively few native lenses, listed below. There is 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 non-M DSLR.^[1]

The EOS EF-M system was discontinued in October 2023.^[2]

Compatibility

The cameras that can use the EF-M mount are:

!Camera!Sensor!Maximum Resolution!Autofocus System!Shutter Speeds!Continuous Shooting!Date Introduced!Weight
EOS M	22.3 × 14.9 mm CMOS (APS-C type)	18 Mp (5184 × 3456)	Hybrid CMOS AF	30 s to 1/4000 s and bulb	4.3 fps	2012-06	262 g (9.2 oz)
EOS M2	22.3 × 14.9 mm CMOS (APS-C type)	18 Mp (5184 × 3456)	Hybrid CMOS AF	30 s to 1/4000 s and bulb	3.4 fps	2013-12	274 g (9.7 oz) including battery
EOS M3	22.3 × 14.9 mm CMOS (APS-C type)	24 MP (6000 × 4000)	Hybrid CMOS AF III	1/4000s to 30 s	4.2 fps	2015-02-06	366 g (12.9 oz) including battery
EOS M5	22.3 × 14.9 mm CMOS (APS-C type)	24 MP (6000 × 4000)	Dual-Pixel CMOS AF	30 s to 1/4000 s	9 fps; 7 fps with autofocus	2016-09-15	427 g (15.1 oz)
EOS M6	22.3 × 14.9 mm CMOS (APS-C type)	24 MP (6000 × 4000)	Dual-Pixel CMOS AF	30 s to 1/4000 s	9 fps; 7 fps with autofocus	2017-02-14	390 g (13.8 oz)
EOS M6 Mark II	22.3 × 14.9 mm CMOS (APS-C type)	32 MP (6960 × 4640)	Dual-Pixel CMOS AF	30 s to 1/4000 s; electronic 1/16000 s	14 fps with autofocus	2019-08-28	408 g (14.4 oz)
EOS M10^[3]	22.3 × 14.9 mm CMOS (APS-C type)	18 Mp (5184 × 3456)	Hybrid CMOS AF II	30 s to 1/4000 s	4.6 frames per second	2015-10-13	301 g (10.6 oz) including battery
EOS M50	22.3 × 14.9 mm CMOS (APS-C type)	24 MP (6000 × 4000)	Dual-Pixel CMOS AF	30 s to 1/4000 s	10 fps; 7.4 fps with autofocus	2018-03-23	387 g (13.7 oz)
EOS M50 Mark II	22.3 × 14.9 mm CMOS (APS-C type)	24 MP (6000 × 4000)	Dual-Pixel CMOS AF	30 s to 1/4000 s	10 fps; 7.4 fps with autofocus	2020-10-14	387 g (13.7 oz)
EOS M100^[4]	22.3 × 14.9 mm CMOS (APS-C type)	24 MP (6000 × 4000)	Dual-Pixel CMOS AF	30 s to 1/4000 s	6.1 fps; 4 fps with autofocus	2017-08-29	302 g (10.7 oz) including battery
EOS M200	22.3 × 14.9 mm CMOS (APS-C type)	24 MP (6000 × 4000)	Dual-Pixel CMOS AF	30 s to 1/4000 s	6.1 fps; 4 fps with autofocus	2019-09-25	299 g (10.6 oz) including battery

List of EF-M lenses from Canon

Focal length	Equivalent focal length (×1.6 crop factor)	Aperture range	Introduced	Min focusing distance	Filter size	Lens diameter	Lens length	Weight
11–22 mm	18 – 35 mm	4 – 5.6	2013	0.15m/0.5ft	55 mm	60.9 mm	58.2 mm	220 g
15–45 mm	24 – 72 mm	3.5 – 6.3	2015	0.25m/0.8ft	49 mm	60.9 mm	44.5 mm	130 g
18–55 mm	29 – 88 mm	3.5 – 5.6	2012	0.25m	52 mm	60.9 mm	61.0 mm	210 g
18–150 mm	29 – 240 mm	3.5 – 6.3	2016	0.45m/1.5ft	55 mm	60.9 mm	86.5 mm	300 g
55–200 mm	88 – 320 mm	4.5 – 6.3	2014	1.0m/3.3ft	52 mm	60.9 mm	86.5 mm	260 g
22 mm	35 mm	2	2012	0.15m/0.49ft	43 mm	60.9 mm	23.7 mm	105 g
28 mm	45 mm	3.5	2016	0.097m (1:1), 0.093m (1.2:1)	43 mm	60.9 mm	45.5 mm	130 g
32 mm	51 mm	1.4	2018	0.23m/0.76ft	43 mm	60.9 mm	56.5 mm	235 g

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

Manufacturer	Focal length	Equivalent focal length (×1.6 crop factor)	Aperture range	Introduced	Filter size
Tamron	18 – 200 mm	29 – 320 mm	3.5 – 6.3	2014	55 mm
Sigma	16 mm	26 mm	1.4	2019	67 mm
Sigma	30 mm	48 mm	1.4	2019	52 mm
Sigma	56 mm	90 mm	1.4	2019	55 mm
Viltrox	23 mm	37 mm	1.4	2020	52 mm
Viltrox	33 mm	53 mm	1.4	2020	52 mm
Viltrox	56 mm	90 mm	1.4	2020	52 mm

Notes and References

Web site: Canon EOS M hands-on preview. DPReview.
News: Canon Japan formally discontinues the last EOS-M cameras, saying goodbye to EF-M. Richard Butler. Digital Photography Review. 21 October 2023.
Web site: Canon U.S.A., Inc., Announces New Feeding Accessory and Fiery-powered Controllers for the imagePRESS C910 Series . 2020-07-22.
Web site: Step Up and Explore the Wonders of Photography With the Compact Yet Powerful New Canon EOS M100 Camera . Canon U.S.A., Inc. | Press Release Details.