The Nikon F-Mount G Lens to FUJIFILM X-Mount Camera Speed Booster ULTRA from Metabones improves upon the original Metabones Speed Booster with a 5 element/4 group optical design that incorporates ultra-high refractive index tantalum-based glass for improved sharpness and reduced distortion and vignetting. The Speed Booster ULTRA allows a full frame Nikon F-Mount G lens to be mounted to an APS-C format X-Mount camera and in doing so, increases the angle of view and increases the maximum aperture by approximately one f/stop. It is compatible with NIKKOR F mount and F Mount G lenses including AI and non-AI mounts.

When a lens intended for full frame sensors or 35mm film is mounted to a camera with an APS-C sized sensor, it transmits a larger area of light than the smaller sensor was built to accept and therefore the effective angle of view of the lens increases. The Speed Booster condenses light from the lens and projects it onto the APS-C sensor allowing the sensor to utilize all of the lens' light and effectively reduces the crop factor of and APS-C E-Mount camera from 1.5x to 1.07x, producing a full-frame angle of view with an APS-C sensor. A corresponding increase in the maximum aperture of one f/stop makes the lens more effective in low-light situations and able to create a shallow depth of field. 

Although the lens will fit physically, automatic diaphragm (AE metering), or other auto functions are not retained using this speed booster. A built-in clickless aperture control ring enables manual control of aperture from the speed booster. This 8-stop ring with clearly marked 1/2-stop markings is shipped as clickless. Metabones Speed Boosters are quality made, using precision-machined brass with chromium plating on both the camera body and the lens side of the booster in order to ensure smooth mounting, quality aesthetic, and durability. A matte black interior reduces internal reflections and a black satin finish external surface matches with most camera bodies and lenses. This adapter has a tripod foot that is compatible with Arca Swiss, Markins, and Photo Clam ball heads, and can be removed if needed with an included hex key.

Nikon F-Mount G Lens to FUJIFILM X-Mount    Ultra-High Index Tantalum-Based Glass    Increases Maximum Aperture by 1 f/Stop    Increases Angle of View by 0.71x    Long-Throw Clickless Aperture Ring    Compatible with Nikon G Lenses    Infinity Focus Adjustment    Detachable Tripod Foot    Black Matte Interior; Black Exterior

Allows a full frame Nikon F-Mount G lens to be mounted to an FUJIFILM X-mount APS-C format camera and in doing so, increases the angle of view and increases the maximum aperture by one f/stop.

The Speed Booster ULTRA design incorporates ultra-high index tantalum-based optical glass for enhanced optical performance with improved corner sharpness and reduced distortion and vignetting. This glass technology and optical design perform extremely well with professional-grade f/2.8 zoom lenses and high-speed fixed focal length lenses such as a 50mm f/1.2 which will perform as a 35.5mm f/0.9 lens with high contrast and resolution from the center to the edges of the image.

Precise fit and solid connection - lens has no play, gap or wiggling when mounted on speed booster and no adjustments are required to fit your lens. Both the camera-side and the lens-side of the speed booster are made of brass which is precision-machined and chrome-plated.

The Speed Booster uses matte-black treatment to keep internal reflection to a minimum in order to maintain the maximum optical quality possible with the lens. The exterior features a black satin surface finish.

A built-in clickless aperture control ring enables manual control of aperture from the speed booster. This 8-stop ring with clearly marked 1/2-stop markings is shipped as clickless.

The speed booster is compatible with NIKKOR F mount and F Mount G lenses including AI and non-AI mounts.

Designed to reach infinity focus while maintaining the correct registration distance required to maintain optical quality of CRC lenses or lenses with floating elements.

The speed booster features a detachable tripod foot which is compatible with Arca Swiss, Markins, Photo Clam ball heads. The booster may attach to a quick release plate or tripod using a 1/4"-20 screw.

Although the lens will fit physically, automatic diaphragm (AE metering), or other auto functions will not be retained using this speed booster.

Two hex keys included with the product, one to detach the tripod foot and another to tighten a mounting screw

Related Questions and Answers

Q: 1. The description doesn't mention autofocus -- just to confirm, this is the newest version that allows PDAF autofocus on Fuji cameras?

A: This is the newest version that allows PDAF on Fuji cameras. The model number for is the X-BT1.

Q: 2. How fast is it compare to fringer?

A: The Fringer does not increase speed

Q: 3. Can anyone confirm that this adapter works properly (and especially that it will allow me to obtain infinity focus on a Sony FS5) with zf.2 mount Zeiss Milvus 25, 35 f1.4, Milvus 50mm f2 Makroplanar and zf.2 (non-Milvus) 135 f2 APO? Thanks

A: While no one has reported using the outstanding Milvus line of lenses with this adapter and that camcorder, we see no reason it should not work as intended.

Q: 4. I cant find a dedicated Speed Booster for Nikon F mount to Fuji X. I need to be able to connect a Samyang 24mm (Nikon F mount) to the Metabones Speed Booster, however I'm worried that because the Speed Booster is for an 'F mount G lens' that the F mount (non-G) lens wont work, or be able to change focus or aperture. Any experience with this? Thanks,

A: The metabones will work perfectly. You don't need to have G lenses for the adapter to work 100%.

Q: 5. I bought this adapter to try using The Nikkor PC lens 24mm and the PC 19mm on my Fuji xt2. Although it mounts and shoots, I cant change the aperture even though the 24 has an aperture ring. It works flawlessly with a 50mm f1.8 prime though. The pc lenses are not on the metabones list of lenses that dont work. Any suggestions?

A: Make sure that the camera menu says shoot without lens. That is the main reason folks have problems with these lens adapters on Fuji cameras. Once you are up and running, both the aperture and the f/stop are manual. I do not know about the manual aperture not working on the 24mm, I cannot see why it would not. However, I would say that in any event, the aperture on the adapter would be the way to go.

Q: 6. When it says that certain Leica R lenses need to be modified to be used on this, what does that mean?

A: There is a small metal lip that needs to be removed (with a metal saw/file) on the back of some Leica lenses (listed on the Metabones web site), otherwise it will hit the SpeedBooster's glass element. There is a risk of damaging the lens when removing this lip, so I asked a repair shop to do it for me. I don't think the lip has a mechanical function, but it prevents the back element of the lens to be scratched if you lay the lens on a table. So you will have to be extra careful how you handle the lens after you remove the lip.

Q: 7. Does it work with the teleconverter Nikon TC-20F?

A: No, the Metabones Nikon F-Mount G Lens to FUJIFILM X-Mount Camera Speed Booster does not work with the Nikon TC-20F. The Nikon TC-20F works only with the following lens Nikon 70-200mm f/2.8 Nikon AF-S NIKKOR 200mm f/2G ED VR II Nikon AF-S NIKKOR 300mm f/2.8G ED VR II Nikon AF-S NIKKOR 300mm f/4E PF ED VR Nikon AF-S NIKKOR 400mm f/2.8D ED-IF II Nikon AF-S NIKKOR 400mm f/2.8E FL ED VR Nikon AF-S NIKKOR 500mm f/5.6E PF ED VR Nikon AF-S NIKKOR 70-200mm f/2.8E FL ED VR Nikon AF-S NIKKOR 70-200mm f/2.8E FL ED VR 100th Anniversary Edition

Q: 8. Viltrex lens adapter Nikon f to Fuji

A: Yes, there is a Viltrox Nikon-Fuji adapter. Click the link below to view; https://www.bhphotovideo.com/c/product/1456834-REG/viltrox_nf_fx1_manual_mount_adapter_for.html

Q: 9. Given that the lens will be completely manual once I have set the aperture how do I know which shutter speed to set?

A: With the Metabones Nikon F-Mount G Lens to FUJIFILM X-Mount Camera Speed Booster ULTRA, for photos you determine the shutter speed based on the available light, focal length, ISO, and aperture.

Q: 10. What's the difference between this model (MEMBSPEFXBT1) and the CINE model (MEMBSPEFXBT2)?

A: The Metabones Canon EF to FUJIFILM X-Mount T CINE Speed Booster ULTRA 0.71x Adapter differs from the Metabones Canon EF Lens to FUJIFILM X-Mount Camera Speed Booster ULTRA in that it offers a locking mechanism on for added stability.