Limitations

• Each lens needs to go through a calibration procedure <click to view> when first used. EF-X Mount Speed Booster ULTRA or EF-X Mount Smart Adapter will gather metadata by turning focus to infinity and minimum when the power is turned ON for the first time. If the lens has a focus limiter switch, set it to FULL prior to turning on the camera. Set camera to AF-S and use the autofocus a few times, although during the initial calibration stage the AF performance may be subpar and you may experience difficulty locking onto subjects. For a zoom lens, it is also necessary to zoom to both the wide end and the telephoto end of the zoom range. Turn off the camera to complete the calibration procedure. If calibration is successful the Speed Booster ULTRA or Smart Adapter will no longer turn focus to minimum the next time the camera starts up. If this calibration procedure is not completed properly, there may be problems such as excessive hunting, difficulty locking onto targets, inaccurate AF, incorrect parallax correction on X-Pro series and incorrect distance scale display on the camera (if enabled).
• Continuous autofocus (AF-C) and video autofocus may not work on some cameras such as X-T100. Increasing FOCUS SENSITIVITY and decreasing AF SPEED is required under the AF-C CUSTOM SETTING (MOVIE) menu.
• For video, aperture priority or manual exposure is recommended to avoid exposure flickering. Fujifilm cameras require fine aperture control but EF lenses are not capable of controlling the aperture with sufficient granularity.
• AF+MF and lens aberration correction are not supported. 
• Distance displayed by camera is approximate but may not match the lens' distance scale. Older optics which do not report distance information will display an incorrect distance on the camera.
• Parallax correction on X-Pro series is approximate and may not be accurate. Older optics which do not report distance information do not support parallax correction at all. All but the smallest EF lenses block a significant portion of the optical viewfinder.
• AF Range Limiter is supported only on newest Fujifilm cameras and require distance information support from the lens. If the option is greyed out try setting it in movie mode.
• The adapter has no aperture ring. On a camera with no mode dial, configure the "APERTURE SETTING" menu option to "AUTO+MANUAL" and use the camera's front or rear dial to change aperture. The auto setting comes after the minimum aperture.
• Aperture diaphragm in Programmed and Shutter Priority exposure modes may make frequent noises with older lenses. In reality, all Fujifilm X-Mount lenses make frequent aperture diaphragm moves during use but native lenses and the latest adapted lenses taking advantage of Metabones' smooth iris feature can do so quietly without making noticeable tick noises.
• With IS/OS/VC lenses the IS MODE setting is ignored and both SHOOTING ONLY and CONTINUOUS modes behave in the same way which is similar to a Canon camera but different from what Fujifilm OIS lenses do. This is done to maximize IS effectiveness. A negative consequence of this is that there may be no OIS during focus check.

 Compatible Lenses

 Incompatible Lenses

• Canon CN Cinema Lens_{(see note 1)}

• Canon EF Lens

• Canon EF Extender 

• Carl Zeiss ZE Lens

• Sigma EF Lens

• Tamron EF Lens

• Tokina EF Lens

• Contax N lenses modified by Conurus

• Canon EF Extender 1.4x (all versions)

• Canon EF Extender 2x (all versions)

• Laowa 200mm F/2.0
• Tamron 70-300mm F/4-5.6 VC USD A005
• Tokina Opera 50mm F/1.4

 Limitations 

No Lens OIS/VC Support

• Tamron SP 15-30/2.8 VC USD A012 
• Tamron 150-600mm F/5-6.3 VC USD A011 
• Tamron 28-300mm f/3.5-6.3 XR Di Macro A06

 Cannot zoom to widest position even after modification

• Canon EF-S 18-135mm F/3.5-5.6 IS STM
• Canon EF-S 18-135mm F/3.5-5.6 IS USM (Nano)

 No AF Support

• Tamron SP 17-50mm F/2.8VC B005
• Tamron 28-300mm F/3.5-6.3 VC A20
• Sigma 18-125mm F/3.5-5.6DC OS HSM

 No Iris Support without External Power Supply

• Canon EF24-70mm F/2.8L USM (I) 
• Canon EF100mm F/2.8 USM Macro (non-L)
• Tamron 18-270mm F/3.5-6.3 VC PZD B008

 AF may not be accurate

• Canon EF 50mm f/1.8 II 
• Canon EF 28-70mm f/3.5-4.5 II
• Sigma 50mm f/1.4 EX HSM
• Tamron 18-250mm f/3.5-6.3 Di II Macro A18
• Tamron 24-70mm f/2.8 VC USD A007
• Tamron 28-300mm f/3.5-6.3 XR Di Macro A06
• Tokina AT-X PRO 11-16mm f/2.8 DX (I)

Unsupported List 

• Native teleconverters
• Lens correction such as peripheral shading, CA and distortion 
• AF may not work if the maximum aperture of the lens plus any EF Extender or other teleconverter attached is smaller than f/8.
• Some early film-era lenses have a large amount of backlash and may not be able to achieve the AF accuracy required for digital cameras. Old lenses with faulty sensors due to wear and tear may lead to AF problems on a mirrorless camera even though the lens may appear to function normally on a DSLR.
• Focus confirmation "chip" (e.g. Dandelion)
• M42 screw mount adapters _{(see note 3)}
• Stacking non-Metabones/non-Conurus mount adapters on top (see note 3 and list of lenses which require modification below.)

Leica R

Super-Elmar-R 15mm

Elmarit R 28/2.8

Elmarit R 35/2.8

Summicron R 50/2

Nikon F

20/2.8 AI-S

Olympus OM

OM 18/3.5

OM 21/2

OM 21/3.5

OM 28/2.8

OM 50/1.8

Pentax K

Every Pentax K-mount lens has a protruding fin and an aperture lever. It does NOT fit.