Since one screen may not fit all video, masking systems have become a popular amenity in home theaters. Powered by an electric motor black fabric masking slides over portions of the screen to alter its shape. In many cases, the fabric panels move over the screen from the top and bottom, effectively making a wide screen horizontally narrower. These are called horizontal masking systems. Several stopping points can be programmed into the system, creating several different aspect ratios, including 2.35:1 (CinemaScope), 16:9 (high-def TV) and 4:3 (standard def TV). It’s an extremely versatile solution … and also expensive and sometimes unnecessary, says Lance Anderson, president of Admit One Cinema, Edina, Minn.
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