When watching movies at home, you may have noticed that some films don’t take up the entire screen. Instead, there are black bars at the top and bottom of the picture. This is due to differences in aspect ratios between how a movie was filmed and your TV screen size and shape.
What is Aspect Ratio?
Aspect ratio refers to the width of an image in relation to its height. It’s expressed numerically, such as 16:9 or 21:9.
For example:
- A 16:9 aspect ratio means the width is 16 units and the height is 9 units.
- A 21:9 aspect ratio means the width is 21 units and the height is 9 units.
Some common aspect ratios include:
| Aspect Ratio | Name | Dimensions |
|---|---|---|
| 16:9 | Widescreen | Landscape rectangular shape, width greater than height |
| 21:9 | CinemaScope | Very wide landscape rectangular shape |
| 4:3 | Standard | More square shape, width similar to height |
The aspect ratio of a movie or TV show refers to the dimensions in which it was shot. The aspect ratio of a TV refers to the shape and size of the screen.
Common Aspect Ratios in Film and TV
There are two main aspect ratios used in the film and TV industries:
- 16:9 – The most common widescreen cinematic aspect ratio today. It is also the standard aspect ratio for HDTVs.
- 21:9 – An even wider cinematic aspect ratio commonly known as CinemaScope. It provides a more panoramic image.
Older movies and TV shows used different aspect ratios:
- 4:3 – The standard aspect ratio for early television sets. It is more square shaped compared to widescreen 16:9.
- 1.85:1 – A standard widescreen ratio developed in the 1950s. Slightly wider than 16:9.
- 2.35:1 – An early widescreen format that later influenced 21:9 ratios.
Why Black Bars Appear
Black bars appear when the aspect ratio of your TV does not match the original aspect ratio of the movie or show you are watching.
For example:
- A 16:9 movie on a 21:9 screen will have black bars on the top and bottom.
- A 21:9 movie on a 16:9 screen will have black bars on the left and right.
- A 4:3 show on a 16:9 screen will have black bars on the left and right.
This happens because a 16:9 movie is designed to fit perfectly on a 16:9 screen. Putting it on a wider or narrower screen results in unused space that appears black.
Common Reasons for Black Bars
Here are some common reasons you may see black bars when watching movies and TV:
| Reason | Example |
|---|---|
| Older 4:3 aspect ratio film or TV show displayed on a 16:9 screen | Seinfeld reruns broadcast in HD |
| Movie filmed in 21:9 aspect ratio shown on a 16:9 TV | The Hateful Eight on Blu-ray |
| 16:9 video streamed or broadcast with pillarboxing | YouTube videos on a smart TV app |
| Movie theater film projected onto different aspect ratio screen | IMAX or 4DX versions of movies |
Older 4:3 Shows/Movies on 16:9 Screens
Most films and TV programs made before the mid-2000s were produced in a 4:3 aspect ratio. However, since the switch to HDTV, standard televisions now have 16:9 widescreen displays. This means older 4:3 content gets pillarboxed with black bars on the sides to fit the wider screen.
21:9 Movies on 16:9 Screens
Some modern blockbuster movies are filmed in extra-wide aspect ratios like 21:9 ( CinemaScope). This creates a panoramic effect on theater screens. However, home Blu-ray releases have to be letterboxed with black bars on a conventional 16:9 television. The full 21:9 image would not fit unless you owned an ultra-widescreen TV.
16:9 Video with Artificial Pillarboxing
Some video streaming services and broadcasters will add artificial pillarboxing to 16:9 video displayed on a 16:9 screen. This is done to maintain a consistent frame size across different programs, some of which may have wider or narrower aspect ratios.
Theaters Showing Different Aspect Ratios
Movie theaters may have screens at different aspect ratios, such as IMAX or 4DX theaters. A film will be letterboxed if the theater screen’s aspect ratio does not precisely match the original aspect ratio of the movie.
Options for Filling the Screen
If you wish to watch movies and TV shows without black bars, there are a few options:
- Widescreen TV/Monitor – Purchase a 21:9 ultrawide display that can show most films in their original aspect ratios.
- Zoom/Crop – Televisions usually have a zoom or crop mode that fills the screen but cuts off the sides of the image.
- Anamorphic Lens – Special oval-shaped lenses can widen the image on a 16:9 screen to fill 21:9 movies.
However, film purists generally recommend against zooming or cropping, since it results in a loss of image quality compared to watching in the original aspect ratio.
Conclusion
Black bars appear when the aspect ratio of your display does not match the original aspect ratio of the film or TV program you are watching. This unused space shows up as letterboxing or pillarboxing.
Common reasons for black bars include older 4:3 content on widescreen TVs, modern theatrical films in 21:9, and video pillarboxed to maintain size. Options to fill the screen include new displays, zooming, and lens attachments. But this comes at the cost of reduced image quality.
Overall, black bars are simply a byproduct of aspect ratio mismatches between filming and viewing. As TV and movie standards evolve, black bars may eventually disappear. But for now, they remain a minor annoyance we have to live with for the optimal viewing experience.