Aspect Ratio of the Video Frame
The ratio of horizontal to vertical dimensions of a film or video frame is called the
aspect ratio. Aspect ratio is independent of absolute image size or resolution.
Aspect ratio can be expressed as absolute dimensions (4 x 3), a ratio (4:3), a fraction
(4/3), or as the decimal equivalent of a ratio (1.33:1, or simply 1.33).
 Video aspect ratios are often written as ratios, such as 4:3 for SD video or 16:9
for HD video.
 Film aspect ratios are often written as decimal equivalents, such as 1.33, 1.85, and
2.40. The higher the decimal number, the wider the image. An aspect ratio of 2.40
is wider than 1.85, and 1.85 is wider than 1.33.
 Digital video resolutions are usually written as absolute pixel dimensions, such as
720 x 480, 1280 x 720, 1920 x 1080, and so on.
Widescreen cinema
2.40:1
Standard cinema
1.85:1
High definition
1.78:1
(16 x 9)
Standard
definition
1.33:1
(4 x 3)
Appendix A
Video Formats
381
V
Below is a list of commonly used aspect ratios, mostly from the film and television
industry, plus a few others for comparison.
Footage with different aspect ratios can be combined using a variety of techniques.