Both freshly-announced Metabones EF-GFX Smart Adapter and 1.26x Smart Expander allow mounting full-frame Canon EF lenses on FUJIFILM GFX medium format cameras while providing electronic lens communication for AF, IBIS, smooth iris, and EXIF data. The Expander multiplies focal length and f-stop of the lens by 1.26x and covers the entire GFX sensor.
The idea of adapting full-frame lenses on medium format cameras is not entirely new. In the case of FUJIFILM GFX medium format cameras, the selection of native G-Mount lenses is not very large and lenses with Canon EF mount happen to be in the kit of most filmmakers already, so why not make use of them? In the past we have seen such adapters already – there is, for example, the Laowa Magic Format Converter with an optical element or FotodioX Vizelex Cine ND without optical expander (but with a built-in V-ND filter). Kipon also makes such an adapter.
When it comes to lens mount adapters with optical elements, I think Metabones usually produces a good image quality. The company now introduces two new adapters – Metabones EF-GFX Smart Adapter and 1.26x Smart Expander. Let’s take a short look at these.
Metabones EF-GFX 1.26x Smart Expander
The idea behind this focal expander is the exact opposite of Metabones’ popular focal reducers – so-called Speed Boosters. This expander multiplies both focal length and F-stop of the lens by 1.26x, enlarging the image circle to cover the entire sensor of FUJIFILM GFX medium format cameras. The diagonal FOV (field-of-view) of the lens remains the same as when mounted natively to a full-frame EF-mount camera.
To name a few examples of popular EF lenses – a 24-70mm f/2.8 lens “becomes” a 30-88mm f/3.5, 70-200mm f/2.8 lens becomes an 88-252mm f/3.5, and the 50mm f/1.4 lens becomes a 63mm f/1.8 lens with the Smart Expander in use. Metabones claims that the expander works well with ultra-wide angle lenses as well. The 11-24mm f/4 Canon EF lens becomes a 13.8-30.2mm f/5 without any vignetting or corner aberrations.
The optical design of the Metabones EF-GFX Smart Expander has been, as always, made by Caldwell Photographic. It consists of 5 elements in 3 groups, and incorporates ultra-high index Lanthanum-based optical glass as well as one element made of fused silica
Furthermore, the Metabones EF-GFX Smart Expander features an electronic lens communication, including phase-detection autofocus (PDAF) and in-body image stabilization (IBIS) on the GFX100, optical image stabilization, and smooth iris. Metabones claims their adapters are the only ones on the market that support IBIS with every EF mount lens.
With lenses that support smooth iris, Metabones EF-GFX makes aperture changes quiet and creates smooth transitions by slowing down the electronically-controlled aperture diaphragm. The button on the Smart Expander toggles between auto aperture (programmed exposure or shutter priority) and manual aperture (aperture priority or manual exposure). For manual lenses, the button brings up the manual lens selection on the camera body so that focal length can be chosen for correct IBIS operation and EXIF.
Metabones EF-GFX Smart Adapter
Metabones also offers a version without the optical element. What about vignetting you ask? In many cases, there will be vignetting and degradation of the image in the corners with EF lenses. Some lenses, however, perform better than others. Canon tilt-shift lenses, for example, cover the whole FUJIFILM GFX sensor. Other zoom lenses will show only very little vignetting towards the middle and long end of the zoom range.
This adapter includes the same electronic lens communication for AF, IBIS, and EXIF as the expander. It also adds a useful feature where the adapter can remember which lenses need to be in 35mm crop mode and which ones cover medium format. This is supposed to save time navigating the camera’s menus for a 35mm crop.
This adapter weighs 168g (the Smart Expander weighs 346g). Both adapters have a black matte satin interior and removable tripod mount with Arca Swiss compatibility.
Known Limitations and Issues
Using adapted lenses is never going to be as smooth as using native lenses. Metabones published a list of known issues and limitations with the initial release of these adapters:
- In some rare cases, lens hoods designed for 3:2 may need to be removed for 4:3 use with Smart Expander.
- Each lens needs to go through a calibration procedure when first used. Refer to the online user manual on Metabones’ web site for instructions.
- Autofocus may have unsatisfactory performance and may not work at all with some lenses
- For video autofocus, increasing FOCUS SENSITIVITY and decreasing AF SPEED are required under the AF-C CUSTOM SETTING (MOVIE) menu.
- AF+MF and lens aberration correction are not supported.
- Some film-era lenses may not be able to achieve a sufficient AF accuracy required for digital cameras. Worn lenses with faulty sensors may lead to AF problems on a mirrorless camera even though the lens may appear to function normally on a DSLR.
- Aperture diaphragm makes frequent noises with older lenses. Use aperture priority and manual exposure modes, or use a lens that supports smooth iris.
- 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.
- MF Distance Display does not work (although AF Distance Display does if the lens transmits distance information).
The good thing is, that some of these issues might get fixed or improved with future firmware updates. All Metabones adapters have a MicroUSB port for firmware updates.
Price and Availability
Metabones EF-GFX 1.26x Smart Expander is available right now. The retail price has been set to $729. The optic-free version – EF-GFX Smart Adapter – will be available shortly afterward for $439.
What do you think about the new Metabones EF-GFX adapters? Do you like the idea of using full-frame EF lenses on a medium format camera? Let us know in the comments underneath the article.