Product Description If you have a SLR or DSLR camera and other maker/mount lenses, the Fotodiox Mount Adapters allow you to use your lenses on the film/digital camera body. Sharing lenses has some distinct advantages. Certain prime lens just can't be replaced, and you save the cost of purchase on new lenses. Fotodiox offers a range of adapter from large format to smaller format digital adapters. Adapting larger format lens to smaller format sensors (i.e: large format to medium format, medium format to 35mm, 35mm to micro 4/3) provides excellent edge-to-edge sharpness. The smaller image field helps minimize the effects of lens distortion and aberration by using the 'sweet spot' or center of the larger lens image circle. The blue dial on the adapter is a built-in 10-stop variable ND filter which allows you to control the amount of light coming in from the lens with a quick twist of the dial. Great for video as you are able to shoot in bright daylight with a shallow depth of field, also allows you to move from bright to dim locations and adjust the light on the fly via the adapter. As with all Fotodiox Pro series adapters, these adapters have been specially crafted to endure professional use. The leaf spring design in the adapter holds the lens tight to the camera body ensuring there is no play between the camera and the lens. The all metal design and polished surface is designed to guarantee a smooth mounting and long lasting experience. With unique styling, the lens mount adapter maintains a professional appearance. Although the lens will fit physically, automatic diaphragm, auto-focusing, or any other functions will not operate correctly while using this adapter. Because of this "stop-down mode" will need to be used when metering since the lens does not have the ability to have its aperture controlled by the camera body. You can shoot with manual mode or aperture priority mode. Infinity focusing is guaranteed. Box Contains Lens Mount Adapter