This adapter gives you the ability to use your irreplaceable prime lens with your new camera and saves you the cost of purchasing new lenses. Fotodiox 'Pro' Series adapters are made with precision and pristine award standards to insure the perfect fit for your camera and lens and to endure professional use. There is No "play" between lens and Camera for a secure fit due to the leaf springs which emulate the camera body. The unique styling maintains/enhances professional appearance. Automatic diaphragm, auto-focusing and other functions will not operate correctly while using this adapter as it is not electronic. In this case, "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. Infinity focusing is guaranteed..