Anamorphic
Anamorphic techniques use special lenses or electronics to squeeze a widescreen
image to fit in a narrower aspect ratio. During projection or playback, the squeezed
image is stretched back to its original widescreen aspect ratio.
Anamorphic video can also be letterboxed. For example, 16:9 anamorphic DVDs may
contain letterboxed 2.40 aspect ratio footage.