Fujifilm G (GFX) mount
Fujifilm · 2017–
| Flange focal distance | 26.7 mm |
|---|---|
| Throat diameter | not published by the manufacturer |
| Type | Mirrorless |
| Formats | medium-format |
| Electronic contacts | Yes |
| Third-party autofocus | Restricted by the manufacturer |
43.8×32.9 mm sensor. Its long flange distance and huge throat mean it takes very little by adaptation apart from other medium-format glass.
Putting other lenses on a Fujifilm G (GFX) body
Nothing researched yet for this body.
Putting Fujifilm G (GFX) lenses on other bodies
Fujifilm G (GFX) lenses cannot usefully be adapted onto another mount. The mount is electronically controlled and its lenses have no aperture ring, so on a body that cannot speak to them they would sit stuck at a single aperture.
What is Fujifilm G mount?
Fujifilm G is the electronic mirrorless mount used by GFX medium-format cameras and GF lenses. It launched with the GFX 50S in 2017 around a 43.8 × 32.9 mm sensor: about 1.7 times the area of a 36 × 24 mm full-frame sensor, with a field-of-view crop factor of roughly 0.79× relative to full frame.
Fujifilm’s system literature specifies a 26.7 mm flange distance, a 65 mm mount diameter and twelve electronic contacts. “G mount” and “GF lens” refer to the same camera system; GFX is the camera-family name.
Do not confuse it with Fujifilm X mount. X-series cameras use APS-C sensors and a different bayonet. A Fujinon XF lens does not fit a GFX body, and a GF lens does not fit an X body.
The image circle is the important difference
The GFX sensor is larger than full frame, so a lens must project a larger image circle to cover it. Native GF lenses are designed for that rectangle. A lens can be physically adaptable and still produce hard dark corners, smeared edges or coverage that changes with focus distance.
This is why flange arithmetic alone is not enough on GFX. A 35mm SLR lens may leave plenty of room for a glassless adapter, but it was designed to cover a smaller 36 × 24 mm frame. Some lenses cover more than their nominal format and some long lenses cover GFX well; that is a property of the individual optical design, not of the mount family.
Adapting Hasselblad H lenses
Fujifilm makes an official H Mount Adapter G for selected Fujinon HC and Hasselblad H lenses from the GX645AF/H system. It is more than a metal spacer: the body can control aperture and operate the lens shutter, including flash synchronisation up to 1/800 second.
Autofocus does not carry across. Fujifilm’s compatibility chart specifies manual focus for the supported H-mount lenses. The adapter exists for photographers with valuable medium-format glass and for studio work where the leaf shutter matters; it is not a cheap route to a fast autofocus system.
Adapting 35mm and manual lenses
The 26.7 mm flange distance leaves room for many SLR systems, including Nikon F, Pentax K, M42 and Canon EF. Mechanical lenses are the predictable cases: use a plain adapter, set the aperture on the lens, and focus with magnification or peaking.
Electronic Canon EF adapters exist, but autofocus behaviour varies by adapter, lens, body and firmware. Check the exact combination rather than treating “EF-to-GFX autofocus” as one feature. The same warning applies to automatic aperture and stabilisation.
GFX bodies offer crop modes, but cropping does not make a poorly covering lens native. It merely records a smaller part of the sensor. That can be useful for a lens you already own; it is rarely a reason to buy that lens specifically for GFX.
Can GF lenses be adapted to other cameras?
Not usefully. GF lenses are electronic, have a relatively short registration distance for medium format, and are built around a large throat and image circle. Mainstream full-frame mirrorless bodies leave too little space for an adapter that could reproduce the 26.7 mm registration distance, and no licensed electronic route exists.
The practical flow is therefore one way: selected older lenses can go onto a GFX body, but GF lenses stay on GFX.