Please consult us of your lens and camera mount before purchase to get a 100Percent right productSuitable forLens Canon EOS EF EFS mount lens Camera Leica M LM L.M Mount Rangefinder CameraNote'No Lens Attached'Warning Message Appears If your camera indicated lens is not properly installed, please modify the camera menu settings. Usually called the release the shutter the lens is not installed, you can modify the settings to be allowed. Specifically refer to the camera manualInfinity focus position the position of the infinity mark ?of the telephoto lens or super telephoto lens is shifted slightly to the positive side to enable focus adjustment even when focus shift is caused due to temperature changes. The shift range is denoted by an Lshaped line, Be sure to check the focus through the viewfinder even when you shoot at infinity.As Canon's EOS lenses are electronically controlled?most Canon EF mount lenses do not feature a manual aperture ring?so when used on our EOSM4.3, which is a full manual operation adapter ring, the aperture could not be transferred to the camera, it will stop down to its smallest f.stop by default.After Sales ServicePlease contact our professional after sales team for video help or technical support in needed