Pillarbox

n. mailbox (British)

The pillar box effect occurs in widescreen video displays when black bars (mattes or masking) are placed on the sides of the image.It becomes necessary when film or video that was not originally designed for widescreen is shown on a widescreen display, or a narrower widescreen image is displayed within a wider aspect ratio, such as a 1.85:1 image in a 2.35:1 frame. The original material is shrunk and placed in the middle of the widescreen frame. Some older arcade games that had a tall vertical and short horizontal are displayed in pillarbox even on 4:3 televisions. Some films made around 1930 such as City Lights will also appear as pillarbox on 4:3 screens.[1]
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