An autostereoscopic image output device includes an image panel having an array of image pixels defining an image, the image pixels being arranged in rows and columns. An array of parallel lenticular elements is positioned over the image panel, the lenticular elements having optical focal axes that are slanted at an angle (φ) to the image pixel columns. The image output device is operable in first and second modes, with the image panel and lenticular element array rotated by 90 degrees between the modes, thereby providing a landscape mode of operation and a portrait mode of operation, the slant angle φ in the landscape mode satisfies 1≧φ≧½.