Bring new life to vintage work horse lenses The Vizelex ND Throttle is well known for having a built-in variable neutral density filter that offers 1 to 8 stops of light reduction. This concept in adapters has been praised by film makers and now Fotodiox has optimized the adapter for that same crowd. The new Vizelex Cine ND Throttle now feature a geared rotating ring for more precise ND selections and can be used with follow focus accessories. This small change makes the Vizelex Cine ND Throttle a versatile tool for any video shooter. Built-in Variable Density Filter: ND2 - ND256 (1-8 stops) The Vizelex Cine ND Throttle reduces light transmission by one stop when at its 'Min' position. The adapter helps maintain shallow depth of field in bright conditions while eliminating the tedious process of changing filters every time the exposure changes. With the filter positioned in the rear, image quality is better than if the same filter were mounted on the front of a lens. The variable ND filter is made from optical polycarbonate (CR39) for clarity and durability. Precision construction for secure and solid fit 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. Enhanced craftsmanship for demanding professionals Fotodiox adapters are designed with precision tolerance that creates a solid, gap free, no play, no wiggle connection with no adjustments needed.