A display device (120) has a 3D display (160) for emitting at least two views of 3D image data to enable autostereoscopic viewing of 3D image data at multiple viewing positions (182, 184). A processor (140) processes the 3D image data (122) for generating the views for display on the 3D display, and a viewer detector (130) detects a viewer position of a viewer in front of the 3D display. The processor has a viewer conflict detector (141) for detecting and resolving viewer position conflicts. The detector obtains at least a first viewer position of a first viewer via the viewer detector, and detects a viewer position conflict at the first viewer position where said first view and second view do not provide the 3D effect for the first viewer. If so, the detector controls generating the views in dependence of the detected viewer position conflict. At least one of said at least two views as received by the first viewer is dynamically modified to signal or resolve the conflict.