When watching cinema movies on your HDTV or 4K Ultra HD TV, you may still see black bars at the top and bottom of some images, even though your TV has a 16×9 aspect ratio.
What's up with those black bars on my TV?
The term 16×9, also expressed as 1.78:1, means that the TV screen is 16 units wide horizontally and 9 units high vertically.
Regardless of the diagonal screen size in inches or centimeters, the ratio of horizontal width to vertical height (aspect ratio) is constant for HDTVs and 4K Ultra HD TVs.
The reason you see black bars in certain movies is because many movies use a wider aspect ratio than 16×9.
