The Dorr Series VII Adapetr ring 49mm, is a universal thread for attaching auxillery items to lenses. It is used in conjunction with standard adapters to form a more secure attachment, when using heavier coversion lenses.
The Dorr Series VII Adapetr ring 49mm, is a universal thread for attaching auxillery items to lenses. It is used in conjunction with standard adapters to form a more secure attachment, when using heavier coversion lenses.