Metabones Nikon G - X Speed Booster ULTRA 0.71x (MB_SPNFG-X-BM2)
• Industry's best aperture ring covers a 8-stop range markings, clearly indicating actual number of f-stops. No more guesswork! (Patent granted).
• Compatible with both Nikkor G lens & F lens (include non-AI & AI lens mounts).
• Advanced 5-element/4-group optical design incorporating ultra-high index tantalum-based optical glass by Caldwell Photographic in the USA (patent granted).
• Increase maximum aperture by 1 stop.
• Increase MTF.
• Makes lens 0.71x wider.
• The tripod foot is detachable and compatible with Arca Swiss, Markins, Photo Clam ball heads.
Tips: Before mounting your lens to the adaptor, please make sure that the f-stop of aperture ring on the adaptor is turned to "7" (i.e. mounting your lens to the adaptor while only the aperture ring in the adaptor is full closed.).
Remark: This mount is manual aperture control. It does NOT support electronic aperture control.
List of incompatible lenses
Nikkor 2.1cm f/4
Nikkor AI-S 20mm f/2.8
Nikkor E series lens (the diaphragm blades are not operated by mechanical linkage levers, such as Nikkor 105mm f/1.4E, PC-E 24mm, 45mm, 85mm T/S, Nikkor AF-S 70-200mm f/2.8E FL ED VR, Nikkor AF-S 16-80mm f/2.8-4E ED DX VR, and Nikkor AF-S 24-70mm f/2.8E ED VR)