Canon EF lens mount

When Canon EF lens mount is the current lens bayonet mount for Canon mm SLR cameras the Canon EOS series. EF is the term electro -focus, and the bayonet comes apart from a minor exception, only in autofocus cameras and special lenses apart only in the autofocus lenses before. Information transfer between camera and lens takes place exclusively digital.

The EF- S lens mount is a subsequently formed a special form for digital SLR cameras with the APS-C format. The S stands for short back, so a shorter distance between the film plane and the rear element of the lens is meant.

The EF- M bayonet was developed specifically for use with the EOS M. It involves ultra- compact and lightweight lenses.

  • 2.1 Period and meaning
  • 2.2 idea
  • 2.3 design
  • 2.4 Operation
  • 2.5 Foreign Lenses
  • 2.6 cameras with EF- S mount
  • 2.7 Lenses with EF- S mount
  • 3.1 adapters for third-party lens mounts
  • 3.2 cameras with EF- M- bayonet
  • 3.3 Lenses with EF bayonet M
  • 3.4 lenses from other manufacturers with EF- M- bayonet
  • 4.1 Fixed focal length 4.1.1 Wide-angle lenses up to 35 mm
  • 4.1.2 Normal lenses to lightweight telephoto lenses from 40 mm to 100 mm
  • 4.1.3 telephoto lenses from 135 mm to 300 mm
  • 4.1.4 super telephoto lenses from 400 mm
  • 4.2.1 Beginning in super wide angle range up to 22 mm
  • 4.2.2 Starting at the wide angle range between 24 mm and 38 mm
  • 4.2.3 Starting in normal and short telephoto range of 50 mm to 100 mm
  • 4.2.4 Starting the telephoto range from 200mm

EF mount

Period of time

The EF mount there, since March 1987, when it appeared 650 with the first Canon EOS camera, the EOS. It solved in the following years from the Canon FD mount. The EF lens program reached only after 1990, the scope of the FD program. Until August 2012 80 million lenses and telephoto converter with EF mount Canon were produced. In addition, a large number of other manufacturers.


Planning for an autofocus SLR system began in late 1981. Right at the beginning it was decided there, a non- mechanical interface, so creating a completely new lens mount exclusively with digital information transmission. At the same time they designed a future professional camera, which later became the EOS 1 was born. However, the development work on this camera only began in the fall of 1985.


The EF mount is a completely new design that is not compatible with the older Canon FD bayonet. In contrast to this, there is an inner bayonet, which has a larger diameter with 44 mm flange and a larger 54 mm. The information transfer is done via spring-mounted and gold-plated contacts on the camera and contact surfaces, which are also gold-plated, with the lens. These contacts are located below the reflective mirror of the camera. The transmission is digital, as a result, have all EF lenses a built-in microprocessor, autofocus lenses also need a built-in motor for focusing.

The advantages of a built- in lens autofocus motor clarified Canon also from the outset with ultrasonic motors that operate very quietly, and - in ring motors - usually allow a simple manual intervention in the focusing.


The EF lens mount on the camera has a red dot at the top, this must match the red dot facing when attaching the lens. Then, the entire lens is rotated to the right until it snaps into place. To unlock a key is pressed, unlike the last time the FD bayonet located on the camera, not the lens.

EF lenses can only be electrically dimmed, so only when the electrical contacts are connected with those of the camera. Therefore, an adapter is required when the lens is operated in reverse position. EF- bellows is only available from third-party manufacturers, they have a cable connection between the camera and lens.

Apart from a few simple lens can be focused manually with an adjustment all EF lenses. This works even if the lens is not connected to the camera. The autofocus mode is switched with a sliding switch on the lens. In ordinary EF lenses, the adjustment when set to manual focus is mechanically decoupled and can be moved freely. Lenses with Full - Time Manual Focus can also focus manually if they are switched to autofocus. This allows, after focusing corrective action by the camera.

Rely on the manual setting was the Canon EF -M, a camera with EF mount, but without autofocus, which therefore also not called EOS. She was from September 1991 for three years in the Canon program, but had no significant meaning.

Most telephoto lenses have a limit for the Auto Focus, which is turned on with the lens. Then not all of the distance range, but for example, only 2 meters is focused to infinity. This avoids a long lasting focusing when the autofocus does not measure suitable contrast and therefore passes through the entire range.

Data transmission

The data transfer between the camera and lens is done digitally using a serial protocol. Canon has published neither the terminal assignment nor the data transmission protocol used. This particular provides for third-party lenses a hurdle (see compatibility).

The determined by means of reverse engineering pin assignment is in the mirror box looked from left to right:

The data are transmitted bidirectionally with the microcontroller in the area widespread SPI protocol. The data width used is 8 bits.

Sign of a lens:

  • Lens includes pin 2 and pin 3 short
  • Thereupon activates the camera VDD
  • Lens is located via serial bus to detect
  • If everything is ok, the camera also switches to VBAT


All Canon EF lenses work perfectly on all EOS cameras. Older foreign lenses have some problems, so that they no longer work with newer cameras. One of the known causes is a reduction of the supply voltage Vdd of 5 to 3.3 V. The problem can only be eliminated through a change in the electronics of the lens.

Adapter for external lens mounts

Lenses with the previous FD bayonet can not be connected directly. Due to the increased back focus of the EF- bayonet adapter required; this may be an intermediate ring with which the lens but no more can be focused to infinity, or it must have lenses and then provides a teleconverter dar. by-products from other manufacturers exist for this Canon Lens Mount Converter FD- EOS, which certain FD- telephoto lens combines with a 1.26 times the focal length and aperture corresponding to a loss of 2/3-Blendenstufen to an EOS camera.

Lenses with F bayonet connectors, M42, T2, Pentax - K bayonet, Yashica / Contax, Leica R or Olympus OM can also be connected with an adapter. This also applies to some medium format lenses, such as P6 bayonet.

With all adapters aperture and focus setting on the lens must be done manually.

EF- S lens mount

The Canon EF-S lens mount is the camera side an extended EF bayonet, which shall ensure that special lenses, called EF -S lenses can only be connected to selected cameras, namely those with APS -C sensor size, so a form factor of 1.6 to the small screen format. EF lenses can be connected to all EOS cameras.

Period and meaning

The EF- S lens mount was released in September 2003 with the Canon EOS 300D. These and all subsequent APS -C format EOS digital cameras can also record in addition to EF EF -S lenses. The previously published EOS digital cameras for this format can not take EF -S lenses but as these are not provided with the ordinary EF mount. These are the models EOS D30, EOS D60 and EOS 10D.

Cameras with a larger sensor still have the usual EF mount EF -S lenses can not be used on these cameras. These are the EOS -1D with its APS -H sensor according to the format 1.25 ( sensor size 28.7 mm x 19.1 mm) and the EOS -1D X, EOS 5D, EOS 6D as well as their predecessor models ( 1Ds - series and 5D series) all with a small image sensor ( sensor size 35.9 mm × 23.9 mm have ).


The EF- S lens mount to fulfill two tasks:

All other manufacturers are missing a special bayonet. For example, you can use Nikon's DX lenses also on FX cameras, the vignetting at full sensor size. Your back is not enough lens farther into the mirror box.


When EF- S lens mount is a special version of the EF - bayonet. The cameras compatible with the EF - S lens mount can take both EF and EF -S lenses. However, the EF -S lenses can be connected to cameras with an EF - S lens mount, on cameras with EF lens mount will not fit. In addition to the different bayonet the EF-S lenses have also around a hard rubber ring around the rear lens that only fits to the corresponding well of the EF-S bayonet to having their normal EF lens mount to prevent an accidental connection to a camera from the outset. The electrical contacts are unchanged.

The EF -S lenses are designed for APS-C format image and have a smaller image circle, so do not illuminate the full small picture format. This enables opposite the large image circle of a simpler, lighter and cheaper lens design.

Also, do with their rear lens on the camera body protrude. This is possible because the cameras for the APS -C format compared to the full-format cameras have a smaller mirror, which only requires a smaller distance from the sensor plane. To shorten this distance on, the mirror is flipped up the EF - S mount on an eccentric orbit. The closer to the sensor gerückte rear lens offers advantages in the design of wide-angle lenses. Canon lenses for the APS -C format basically have the EF- S mount, even if they do not use the shorter distance.


EF-S lenses have a red circle instead of a white square as a position mark on the lens. A camera with EF -S connector has two markings, the familiar red top on the bayonet for EF lenses and a white right next to it in about one - clock -position for EF -S lenses. As a result, EF -S lenses are not recognized with the notch facing upward but slightly turned to the right. First attempt is to use EF -S lenses on a camera with ordinary EF mount, so missing the appropriate white mark on the camera thread, also the hard rubber ring of the lens prevents the erroneous connection and thus preserves the mirror before a collision with the lens.

The EF -S lenses are labeled with the actual focal length. To get the equivalent focal length for the format of 36 mm × 24 mm, it should be multiplied by the factor 1.6 format.

Foreign lenses

The lenses from other manufacturers for the APS -C format make use of the EF- S mount no use. Always keep a normal distance between film or sensor plane and rear lens. You shoot with these lenses on an EOS camera with a larger sensor, then this leads to shadow ( vignetting ) in the corners. With zoom lenses, this is true at least for the part of wide-angle focal length range.

Cameras with an EF - S lens mount

(All expressed in reverse order of their launch )


  • EOS 1200D
  • EOS 100D
  • EOS 700D
  • EOS 600D
  • EOS 60D
  • EOS 70D
  • EOS 7D


  • EOS 1100D
  • EOS 650D
  • EOS 550D
  • EOS 500D
  • EOS 50D
  • EOS 1000D
  • EOS 450D
  • EOS 40D
  • EOS 400D
  • EOS 30D
  • EOS 350D
  • EOS 20D
  • EOS 300D

Despite Crop 1.6 No EF - S lens mount, but EF mount:

  • EOS 10D
  • EOS D60
  • EOS D30

Lenses with EF- S mount

  • EF -S 10-22 mm f/3.5-4.5 USM
  • EF -S 15-85 mm f/3.5-5.6 IS USM
  • EF -S 17-55 mm f/2.8 IS USM
  • EF -S 17-85 mm f/4-5.6 IS USM
  • EF -S 18-55 mm f/3.5-5.6 IS II
  • EF -S 18-55 mm f/3.5-5.6 IS STM
  • EF -S 18-135 mm f/3.5-5.6 IS
  • EF -S 18-135 mm f/3.5-5.6 IS STM
  • EF -S 18-200 mm f/3.5-5.6 IS
  • 55-250 mm EF-S f/4-5.6 IS II
  • 55-250 mm EF-S f/4-5.6 IS STM
  • EF- S 60mm f/2.8 Macro USM
  • EF -S 18-55 mm f/3.5-5.6
  • ( Made for Japan only ) EF -S 18-55 mm f/3.5-5.6 USM
  • EF -S 18-55 mm f/3.5-5.6 II
  • EF -S 18-55 mm f/3.5-5.6 II USM
  • EF -S 18-55 mm f/3.5-5.6 IS
  • 55-250 mm EF-S f/4-5.6 IS

EF- M- bayonet

The EF- M bayonet found at mirrorless system cameras with APS -C image format use. It was introduced in October 2012 with the EOS M. Because of lost mirror and the reduction to the APS-C format lens to a SLR camera moves closer to the sensor. It has a flange focal length of 18 mm, versus 44 mm in the classical EF mount. This allows the construction flatter camera body and a more compact lens design. The diameter of the EF- M- bayonet is about 7.5 mm smaller than the EF - bayonet. Technically, the EF - M bayonet on the EF mount, which is why EF and EF- S lenses can be used with an adapter on a camera with EF- M- bayonet. The automatic functions of the lens, including image stabilization, are supported. Conversely, can not be used to the usual Canon SLR EF- M lenses.

Adapter for external lens mounts

The reduced flange allows the use of numerous foreign lenses that are designed for a longer flange. So are available from alternative suppliers, for example, the universal adapter for M42 screw mount, Leica M, Leica R, Minolta SR, Pentax K, Nikon F, Canon FD and many other systems. As the camera lenses generally can not control, the lenses have to be set manually. Only one auto ( without aperture metering ) is often possible. For some systems even tilt and shift adapters are available ( eg Nikon F). Since the adjustment mechanism of the adapter requires space, this rather small picture SLR lenses are suitable. Lenses of many Rangefinder Cameras offer with their slightly shorter back focus less room.

Cameras with EF- M- bayonet

  • Canon EOS M
  • Canon EOS M2 (only available in the Asian market )

Lenses with EF bayonet M

  • EF -M 22mm f / 2 STM
  • EF- M 18 -55mm f/3.5-5.6 IS STM
  • EF- M 11 -22mm f/4-5.6 IS STM

Lenses from other manufacturers with EF- M- bayonet

  • Walimex Pro 16mm f2
  • Yasuhara Nanoha Macro x5/x4 f11 -32

Canon EF lenses

Fixed Focal Length

Wide-angle lenses up to 35 mm

  • EF 14mm f/2.8L II USM
  • EF 20mm f/2.8 USM
  • EF 24mm f/1.4L II USM
  • EF 24mm f/2.8 IS USM
  • EF 28mm f/1.8 USM
  • EF 28 mm f/2.8 IS USM
  • EF f/1.4L USM 35 mm
  • EF 35 mm f/2.0 II IS USM
  • EF 14mm f/2.8L USM
  • EF 15 mm f/2.8 Fisheye
  • EF 24mm f/1.4L USM
  • EF 24mm f/2.8
  • EF 28 mm f/2.8
  • EF 35 mm f/2.0

Normal lenses to lightweight telephoto lenses from 40 mm to 100 mm

  • EF 40mm f/2.8 STM
  • EF 50mm f/1.2L USM
  • EF 50mm f/1.4 USM
  • EF 50mm f/1.8 II
  • EF 85mm f/1.2L II USM
  • EF 85mm f/1.8 USM
  • EF 100mm f/2.0 USM
  • EF 50mm f/1.0L USM
  • EF 50mm f/1.8
  • EF 85mm f/1.2L USM

Telephoto lenses from 135 mm to 300 mm

  • EF 135mm f/2.0L USM
  • EF 135mm f/2.8 Soft Focus
  • EF 200mm f/2.0L IS USM
  • EF 200mm f/2.8L II USM
  • EF 300mm f/2.8L IS II USM
  • EF 300mm f/4.0L IS USM
  • EF 200 f/1.8L USM mm (spare parts no longer fully available)
  • EF 200 f/2.8L USM
  • EF 300mm f/2.8L USM
  • EF 300mm f/2.8L IS USM
  • EF 300mm f/4.0L USM

Super telephoto lenses from 400 mm

  • EF 400mm f/2.8L IS II USM
  • EF 400mm f/4.0 DO IS USM
  • EF 400mm f/5.6L USM
  • EF 500mm f/4.0L IS II USM
  • EF 600mm f/4.0L IS II USM
  • EF 800mm f/5.6L IS USM
  • EF f/5.6L USM 1200 mm ( on special order only )
  • EF 400mm f/2.8L USM
  • EF 400mm f/2.8L II USM
  • EF 400mm f/2.8L IS USM
  • EF 500mm f/4.0L IS USM
  • EF 500mm f/4.5L USM
  • EF 600mm f/4.0L USM
  • EF 600mm f/4.0L IS USM

Zoom lenses

Beginning in super wide angle range up to 22 mm

  • EF 8-15 mm f / 1:4 L Fisheye USM
  • EF 16-35 mm f/2.8L II USM
  • EF 17-40 mm f/4.0L USM
  • EF 16-35 mm f/2.8L USM
  • EF 17-35 mm f/2.8L USM
  • EF 20-35 mm f/2.8L USM
  • EF 20-35 mm f/3.5-4.5 USM
  • EF 22-55 mm f/4.0-5.6 USM

Starting at the wide angle range between 24 mm and 38 mm

  • EF 24-70 mm f/2.8L USM
  • EF 24-70 mm f/2.8L II USM
  • EF 24-70 mm f/4.0L IS USM
  • EF 24-105 mm f/4.0L IS USM
  • EF 28-135 mm f/3.5-5.6 IS USM
  • EF 28-300 mm f/3.5-5.6L IS USM
  • EF 24-85 mm f/3.5-4.5 USM
  • EF 28-70 mm f/2.8L USM
  • EF 28-70 mm f/3.5-4.5
  • EF 28-70 mm f/3.5-4.5 II
  • EF 28-80 mm f/2.8-4.0L USM
  • EF 28-80 mm f/3.5-5.6
  • EF 28-80 mm f/3.5-5.6 USM
  • EF 28-80 mm f/3.5-5.6 II
  • EF 28-80 mm f/3.5-5.6 II USM
  • EF 28-80 mm f/3.5-5.6 USM III
  • EF 28-80 mm f/3.5-5.6 USM IV
  • EF 28-80 mm f/3.5-5.6 USM V
  • EF 28-90 mm ​​f/4.0-5.6
  • EF 28-90 mm ​​f/4.0-5.6 USM
  • EF 28-90 mm ​​f/4.0-5.6 II
  • EF 28-90 mm ​​f/4.0-5.6 II USM
  • EF 28-90 mm ​​f/4.0-5.6 III
  • EF 28-105 mm f/3.5-4.5 USM
  • EF 28-105 mm f/3.5-4.5 II USM
  • EF 28-105 mm f/4-5.6
  • EF 28-105 mm f/4-5.6 USM
  • EF 28-200 mm f/3.5-5.6
  • EF 35-70 mm f/3.5-4.5
  • EF 35-70 mm f/3.5-4.5A (only auto focus )
  • EF 35-80 mm f/4.0-5.6PZ ( motorized zoom )
  • EF 35-80 mm f/4.0-5.6
  • EF 35-80 mm f/4.0-5.6 USM
  • EF 35-80 mm f/4.0-5.6 II
  • EF 35-80 mm f/4.0-5.6 III
  • EF 35-105 mm f/3.5-4.5
  • EF 35-105 mm f/4.5-5.6
  • EF 35-105 mm f/4.5-5.6 USM
  • EF 35-135 mm f/3.5-4.5
  • EF 35-135 mm f/4.0-5.6 USM
  • EF 35-350 mm f/3.5-5.6L USM
  • EF 38-76 mm f/4.5-5.6

Starting in the normal and light telephoto range of 50 mm to 100 mm

  • EF 55-200 mm f/4.5-5.6 II USM
  • EF 70-200 mm f/2.8L IS USM II
  • EF 70-200 mm f/4L USM
  • EF 70-200 mm f/4L IS USM
  • EF 70-300 mm f/4.0-5.6 IS USM
  • EF 70-300 mm f / 1:4.0-5.6 L IS USM
  • EF 70-300 mm f/4.5-5.6 DO IS USM
  • EF 75-300 mm f/4.0-5.6 III
  • EF 75-300 mm f/4.0-5.6 USM III
  • EF 100-300 mm f/4.5-5.6 USM
  • EF 100-400 mm f/4.5-5.6L IS USM
  • EF 50-200 mm f/3.5-4.5
  • EF 50-200 mm f/3.5-4.5L
  • EF 55-200 mm f/4.5-5.6 USM
  • EF 70-200 mm f/2.8L USM
  • EF 70-200 mm f/2.8L IS USM
  • EF 70-210 mm f/4.0
  • EF 70-210 mm f/3.5-4.5 USM
  • EF 75-300 mm f/4.0-5.6
  • EF 75-300 mm f/4.0-5.6 USM
  • EF 75-300 mm f/4.0-5.6 IS USM
  • EF 75-300 mm f/4.0-5.6 II
  • EF 75-300 mm f/4.0-5.6 II USM
  • EF 80-200 mm f/2.8L
  • EF 80-200 mm f/4.5-5.6
  • EF 80-200 mm f/4.5-5.6 USM
  • EF 80-200 mm f/4.5-5.6 II
  • EF 90-300 mm f/4.5-5.6
  • EF 90-300 mm f/4.5-5.6 USM
  • EF 100-200 mm f/4.5A
  • EF 100-300 mm f/5.6
  • EF 100-300 mm f/5.6L

Beginning in the telephoto range from 200mm

  • EF 200 -400mm f/4L IS USM Extender 1.4x

Tilt and shift lenses

Although these lenses have electronic shutter transmission, but no autofocus.

  • TS-E 17mm f/4.0L
  • TS-E 24mm f/3.5L II
  • TS-E 45mm f/2.8
  • TS- E 90mm f/2.8
  • TS-E 24mm f/3.5L

Macro and magnifying lenses

  • EF 50mm f/2.5 Compact Macro
  • MP-E 65mm f/2.8 1- 5x Macro Photo ( without autofocus )
  • EF 100mm f/2.8 Macro USM
  • EF 100mm f/2.8L Macro IS USM
  • EF 180mm f/3.5L Macro USM
  • EF 100mm f/2.8 Macro