A switchable autostereoscopic display device comprises a display panel having an array of display pixel elements for producing a display, the display pixel elements being arranged in rows and columns. An imaging arrangement directs the output from different pixel elements to different spatial positions to enable a stereoscopic image to be viewed. The imaging arrangement is electrically switchable between at two 3D modes, wherein the effective position of the imaging arrangement is shifted laterally between the modes with respect to the display pixel elements by an amount which is a non-integer multiple of the pitch between the pixel elements. These two modes enable the resolution per mode to be increased, by adding views at inter-pixel locations, or enables the number of views to be increased.