What I did was used pipe thread tape and wrapped it around the tube portotion of the rear of the lens where the exakta baynet mount is, but first you have to remove the locking screw that is on the back of the lens, its what clicks the release lever of the exakta camera. then you will need a Leica screw mount to alpha mount adaptor they cost about $10 on ebay. it takes about four or five wraps of pipe thread tape to make the exakta mount fit nicely to the Leica screw mount adaptor.