Anamorphic

In order to produce an image for a widescreen movie theater, but not waste film, anamorphic lenses are used. These “squeeze” the image sideways as it goes onto the almost-square film space. Then, at the theater, a reverse anamorphic projection lens “unsqueezes” the image as it is projected onto the screen, producing a long rectangular picture. These days, digital cameras and other technologies can use the anamorphic process with similar results.