The present invention relates to unmanned aerial vehicle for agricultural field assessment. It is described to fly (210) the unmanned aerial vehicle to a location in a field containing a crop. A body of the unmanned aerial vehicle is positioned (220) in a substantially stationary aspect above the crop at the location. A camera of the unmanned aerial vehicle is moved (230) vertically with respect to the body of the unmanned aerial vehicle between a first position and a second position, wherein the first position is closer to the body of the unmanned aerial vehicle than the second position. The camera acquires (240) at least one image relating to the crop when the camera is not in the first position.