An adjustable transfer device for unloading processed crop onto a container of a transport vehicle includes a control arrangement with an electronic control unit, among other integrated components. Electronic control unit calculates position of expected point of incidence of crop flow on the container within field of view of optical image capture device, displays image of container together with symbol representing calculated expected point of incidence of crop flow on container on display, receives adjustment inputs from user interface for adjusting position of actuator and thus of adjustable transfer device, updates position of symbol in image on display, receives confirmation input from user interface once symbol in image on display is in appropriate position, derives at least one feature in image representing container, and tracks container within output signal of image processing system based on retrieved image feature and controls actuator accordingly to fill container with crop.