Canon EF vs. Micro Four Thirds Mount
Comparing 2 standards across 9 specifications. 9 key differences identified.
The Canon EF Mount (introduced in 1987 for the EOS autofocus SLR system) revolutionized photographic camera design as the first 100% all-electronic lens mount, eliminating all mechanical aperture linkages and autofocus drive shafts. Featuring a 44.0 mm Flange Focal Distance and a large 54.0 mm throat diameter, over 150 million EF lenses were manufactured over 33 years.
The Micro Four Thirds Mount, introduced in 2008 by Olympus and Panasonic as the first mirrorless system built as a dedicated open standard (rather than an adapted rangefinder mount, as with the earlier 2004 Epson R-D1), features a 19.25 mm Flange Focal Distance, a 38.0 mm throat diameter, and an 11-pin all-electronic bayonet interface. Governing an open consortium, it is used across OM System, Lumix, Blackmagic Design, and DJI aerial cameras.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Flange Focal Distance (FFD)
|
44.00 mm (1.732 in) | 19.25 mm (0.758 in) |
|
Inner Throat Diameter
|
54.00 mm (2.126 in) | 38.00 mm (1.496 in) |
|
Bayonet Tabs
|
3 locking tabs with clockwise twist | 3 symmetrical stainless steel tabs |
|
Electronic Interface
|
8 gold-plated electronic contacts (expanded to 11 pins on EF super-telephoto lenses for teleconverters) | 11 gold-plated electronic contacts (shared protocol between OM System and Panasonic) |
|
Camera Systems
|
Canon EOS-1D X Mark III, EOS 5D Mark IV, EOS 6D II, EOS Rebel series, Cinema EOS C300/C500 | OM System OM-1 Mark II, Panasonic Lumix GH6 / G9 II, Blackmagic Pocket Cinema Camera 4K, DJI Inspire 3 X9 MFT |
|
Internal Actuators
|
Internal USM (Ultrasonic Motor) in lens body + internal electromagnetic aperture diaphragm (EMD) | — |
|
Variants
|
EF (Full Frame), EF-S (APS-C with rubber bumper back-focus extension), EF-M (discontinued APS-C mirrorless) | — |
|
Historic Milestone
|
— | First mirrorless system built as a dedicated open standard, launched with the Panasonic Lumix G1 (2008) -- the earlier 2004 Epson R-D1 was a mirrorless interchangeable-lens camera, but on an adapted rangefinder mount, not a purpose-built open standard |
|
Consortium Members
|
— | OM Digital Solutions (Olympus), Panasonic, Blackmagic Design, DJI, Sharp, Voigtländer, Laowa |