Aspect Ratio (List of High Width)

It refers to the ratio of width and height for a picture or screen. American television (NTSC standard) uses a more or less square 4:3 (1.33:1). Increasingly, projection TV and direct view (especially digital TV) use the wider relationship of 16:9 (1.78:1) to show better material as wide screen transmissions anamorphic DVD and HDTV.

After the introduction of anamorphic systems such as CinemaScope, the standard academy ratio of 1.37:1 was widened.  This was simply a matter of masking the top and bottom of a standard academy frame to produce a ratio of 1.85:1 called Widescreen.  It is the standard screen format used in cinemas today.

The most popular aspect ratio is 4:3 (4 by 3). In early television and video formats are in the 4:3 aspect ratio, which means that the width of the image is 4/3 times the height. Examples: A 15-inch monitor is 12 inches by 9 inches (9 x 4 / 3 = 12). The resolution of 640 x 480 is a 4:3 (480 x 4 / 3 = 640). Other formats such as 5:4 used by the resolution SXGA 1280 x 1024, 16:9 and 3:2 used by HDTV for 35mm slides.