A Directors viewfinder or director's finder is a Viewfinder used by film directors to see the scene as seen by the camera lens. In appearance it is like a monocular telescope that usually hangs around the neck.
While modern film cameras are relatively light weight, earlier models were quite heavy and moving them required some effort. The director's finder allows the directors to be more productive as they can plan where to place the camera and which lens to select for the camera without the need to move the larger film camera.
Most viewfinders allow different focal lengths and film sizes. In some models also the aspect ratio is selectable. Some viewfinders allow the mounting of cinema lenses.