If you are transitioning to a Fuji X-mount camera system, there may be times when you want to use your existing glass. For this, you need to get a lens mount adapter.
While a lens mount adapter lets you use your Nikon (or Canon) lenses with the Fuji X-mount bodies, there are some major limitations. You will have to use manual focus and set the aperture using a ring on the adapter barrel. Vibration reduction (VR) will not function, either. In my opinion, the reason you get one of these adapters is because you have a particular use for one of your existing lenses. In my case, I like to be able to combine my infrared-converted Fujifilm X-E1 body with my Nikon glass when traveling so that I don’t need to pack two sets of lenses. I have two adapters that I have tested with my Nikon lenses.
The Metabones “Speed Booster” adapter
Because the Fujifilm X-Mount cameras use APS-C format sensors, you lose out on wide focal lengths when you mount full-frame lenses on them. A 16mm lens on the Fuji delivers the same angle of view as a 24mm lens. The Metabones Speed Booster adapter has a lens element inside it that re-focuses the image onto the APS-C sensor format. The adapter delivers a crop factor of 0.71, which when paired with the APS-C crop factor of 1.5, yields an effective crop factor of 1.07. In other words, you get your wide-angle lenses back.
Moreover, by focusing the light from the larger image circle of full-frame lenses, the “Speed Booster” adapter is able to put a brighter image on the sensor. The effect is a light gain of about 1EV. This gives you faster shutter speeds and easier focusing in low-light conditions.
Construction & Build Quality
The Metabones adapter is solidly built. It has all-metal construction, and a clickless aperture ring with a smooth feel. It will work with both AF-D and G-type Nikon lenses. Because G-type Nikkors do not have an aperture ring, it’s important to have the manual coupling in the adapter. There are markings on the aperture ring that correspond to roughly 1-stop increments. The Metabones adapter also includes a removable Arca-Swiss compatible mounting foot. I had to remove the foot when using my X-T1 with a RRS L-Bracket in order to mount it to my ball head.
Angle of view and speed boost
I guess the question at hand is “does it work as advertised?” I tested the adapter out in my living room with a Nikon 16-35mm f/4 AFS G lens and compared it to using the inexpensive Fotodiox lens adapter. I made shots on a tripod with a fixed 200 ISO and manually focused.
With the basic adapter, the scene metered 1/3s at ISO 200, wide-open (f/4). With the Metabones adapter, the same scene metered at 1/7s. This suggests that indeed I got approximately a 1-stop increase in light. You can also see in the sample images below that the Metabones adapter provides a much wider angle of view, as promised.
The Metabones Speed Booster F-mount to Fuji X-Mount adapter delivers on its promise of retaining the full angle of view of Nikon FX lenses and a faster shutter speed, too. At a price of $479, however, most people will probably opt for one of the less expensive alternatives that do not include a glass element, such as the Fotodiox ($69), Metabones ($139), or Novoflex ($279). However, if you use full-frame Nikon lenses, especially wide-angles like the 16-35mm or 14-24mm, then the Metabones Speed Booster is a great way to use this glass with your Fujifilm X-mount camera.