Metabones Nikon G to Micro FourThirds Speed Booster ULTRA 0.71x (Black Matt) (MB_SPNFG-M43-BM3)

If a lens intended for 35mm film or similarly sized full frame as well as APS-C camera sensors is connected to a camera with a Micro Four Thirds-sized sensor, it would project an image larger than the Micro Four Thirds sensor was built to accept. Able to capture only the center portion of the projected image, the effective angle of view of the lens would be narrowed, creating an in-camera "crop factor." The Speed Booster Ultra 0.71x Adapter for Nikon G Lens to Micro Four Thirds-Mount Camera condenses the light from a lens designed for APS-C as well as 35mm film, or "full frame" camera sensors and projects it onto a Micro Four Thirds sensor. This allows a Micro Four Thirds sensor to utilize more of the light gathered by a connected lens, which effectively reduces the crop factor while making available to the sensor an additional 1 stop of light for each of the lens's f/stop settings.

The Speed Booster Ultra 0.71x Adapter for Nikon G Lens to Micro Four Thirds-Mount Camera does not support electronic communication between an attached camera and lens. To help determine the amount of light that enters a Micro Four Thirds-mount camera when using this adapter and a Nikon F-mount lens, an aperture dial is built into the Speed Booster Ultra 0.71x Adapter for Nikon G Lens to Micro Four Thirds-Mount Camera. The aperture dial is designed to provide aperture control for Nikon G-type lenses, which do not have an aperture ring. Nikon AI or many post-Nikon AI lenses can have their aperture settings widened or narrowed using their built-in aperture control rings if preferred.