Patented 5-element/4-group optical design incorporating ultra-high index tantalum-based optical glass by Caldwell Photographic in the USA
Iris/aperture controlled by the camera body
Smooth iris support with the latest Canon (2009+), Tamron (SP series 2013+) and Sigma (2016+) lenses
Image stabilization (IS) lens support
Support for cameras with in-body image stabilization (IBIS), including Panasonic GX7, GX8, GX80/85 and Olympus cameras
Electronic manual focusing (e.g. EF 85/1.2L II and discontinued EF 50/1.0L)
EXIF (focal length, aperture, zoom range)
Distance and zoom display on camcorders (requires lenses supporting distance information)
Cinema EOS lens support
Compatible with all MFT mount cameras, including GH4, OM-D, Blackmagic Cinema Camera, Blackmagic Pocket Cinema Camera.
EF-S lenses require modification to fit or may remain incompatible even after modification (but third party DX lenses can be used without modification)
Some EF-S and DX lenses may not have enough coverage of the entire image circle for stills after widening by 0.71x (but video will have enough coverage).
No video AF for Olympus
AF may not work if the maximum aperture of the lens plus any EF Extender or other teleconverter attached is smaller than f/8 before boost or smaller than f/5.6 after boost.
AFC (continuous AF) and AFF (flexible AF) modes are not supported, except on Olympus OM-D E-M1.
Panasonic video AF may hunt more than a native lens or have unsatisfactory performance.
Some Tamron lenses may have unsatisfactory AF accuracy.
No support for Focus Stacking and Focus Bracketing on Olympus.
On Olympus, other than E-M1, you may move the single AF point among any of the 81, but you may not multi-point AF. There is no restriction on E-M1 and Panasonic.
Very early Olympus models (e.g. E-PL1) have no autofocus support.
EF-mount lenses are not silent but may make audible click noises during autofocus operation and iris changes which may be picked up by the built-in microphone of the camera. An external microphone is recommended for video.
Use of Canon Cinema lenses such as CN-E 18-80mm T4.4L IS KAS S for still photography is not supported.
Iris changes are in 1/8 stop steps which may be noticeable in video recordings. Programmed exposure mode and shutter priority exposure mode should not be used for video. This limitation does not apply to Cinema EOS lenses which permit fine resolution iris control, such as CN-E 18-80mm T4.4 L IS KAS S.
No support for in-camera correction such as peripheral shading, CA and distortion
Camera Body Compatibility List
Olympus: E-M1, E-M1 Mark II, E-M5, E-M5 Mark II, E-M10, PEN-F, E-P5, E-PL3