Understanding Aspect Ratio

What to do with those black bars

There's no doubt that today's high-definition TVs look fantastic. But some HDTV owners are frustrated by the "black bars" that pop up on either side of the screen when they watch regular, non-high-definition shows. In this article, we'll explain why you see them and offer some solutions.

Aspect ratio basics

There are two common TV screen shapes that most folks will recognize the squarish shape of conventional TVs, and the widescreen shape of today's HDTVs. The term used to describe TV screen shape is "aspect ratio" conventional TVs, and some small LCD HDTVs, have a 4:3 aspect ratio; widescreen HDTVs have a 16:9 ratio.

TV shows also typically have a 4:3 or 16:9 ratio. While most new HD programming is in 16:9, a significant amount of digital TV broadcasts are still sent in the conventional 4:3 ratio. And it's the difference in shape between those two ratios that can result in a "pillar boxed" picture those black columns standing to the left and right of your picture, when you watch a conventional 4:3 program on your widescreen TV.

What you can do about the "black bars"

You may choose to keep the black bars on 4:3 sources, or decide to stretch or zoom that picture to fill the whole screen it's a matter of personal preference. Nearly all recent widescreen TVs include one or more viewing modes that fill out the screen's width by stretching, zooming, or stretching and zooming the image. While most people find this effect acceptable for non-critical "background" viewing like the local news, many aren't thrilled when their favorite actors suddenly look noticeably stockier. See the images below to get an idea of how these picture adjustments might look.

4:3 image on a 16:9 screen

When 4:3 programs are displayed on a 16:9 screen, black or gray bars appear on the sides of the screen the image is "pillar-boxed."

4:3 image stretched to fill a 16:9 screen

To get rid of the pillar-box black bars, one option is to use stretch mode. Some sets stretch the image evenly across the screen (as above), though a few stretch the edges only and leave the center undistorted.

4:3 image zoomed to fill a 16:9 screen

Another option is to zoom in on the picture and fill the screen. This cuts off the top and the bottom of the picture, but leaves it undistorted.

16:9 image on a 16:9 screen

When you look at this widescreen version of the image we've been using to show 4:3, you can see just how much of the picture is lost with a 4:3 image.

It's worth noting that zooming and stretching a picture may work better for some shows than others. For example, a crisp digital Discovery Channel show can still look clear and detailed when zoomed or stretched; but lower-quality signals, such as reruns of older shows, can look noticeably more blurry and washed out. Of course, if you're someone who gets distracted by black bars on the side of your screen, you may prefer to go with a somewhat fuzzier picture. It's really up you.

If you do prefer a stretched or zoomed picture, then try to get familiar with the different aspect ratio modes your TV offers. Usually, there's a dedicated button on the remote, often labeled "Wide" or "Aspect," that lets you cycle through several options.

A note about plasma TVs

If you have or plan to buy a plasma TV, you should be aware of the possibility of "screen burn-in." This can happen when static images such as black bars are left on your plasma screen for extended periods of time. The image gets "etched" into the screen, and can be visible even when you're watching other sources. Many plasma owners simply opt to stretch or zoom 4:3 images to be on the safe side. Fortunately, a lot of today's plasmas have features to combat this issue, such as special screen displays designed to erase burn-in, if it happens. Be sure to check the TV's manual for tips and suggestions on avoiding, or correcting, this problem.

Watch a lot of DVDs?

There are a couple of additional things worth noting if you watch a lot of DVDs. Namely, you'll find a range of aspect ratios and aspect ratio options. We've listed them below, along with some tips for watching them on a widescreen TV.

  • Some discs have both 16:9 and 4:3 aspect ratio options you can choose the one that best fits your screen.
  • Many discs offer only 16:9 ("widescreen") or 4:3 ("full screen") make sure you shop accordingly.
  • Some discs feature an "anamorphic" aspect ratio. These movies have extra lines of information inserted in a 4:3 signal, which the TV is then supposed to expand to fill a 16:9 screen. But, depending on the combination of your TV and player, it may not work properly.
  • A few DVDs feature an "ultra-widescreen" aspect ratio known as 2.35:1. Since it's a little bit wider than a widescreen TV, you'll see thin black bars on the top and bottom of the image kind of like you would if you were watching a 16:9 letterboxed movie on an older 4:3 TV. These black bars are thin enough that they don't bother most folks. If you find them distracting, try cycling through your TV's aspect ratio modes to zoom or vertically stretch the image to fill the screen.

Troubleshooting aspect ratio problems

It's important to keep in mind that your TV isn't the only thing in your system that can affect aspect ratio. Your cable box, DVD player, and other source components likely all have their own aspect ratio settings. And the TV show your cable box displays, or the movie in your DVD player, also have their own set aspect ratios. If your TV, source component, and source material aren't all on the same page regarding aspect ratio, some pretty funky things can happen.

To avoid aspect ratio issues as much as possible, here's what we suggest:

  1. As you're setting up your video sources, be sure to go into the picture settings to menu and set it to the proper aspect ratio. The specific terms used in these menus differ, but for a widescreen TV you'll likely see something called "widescreen" or "16:9," for example.
    Video setup

    Use your disc player's setup menu to get a properly formatted picture on your TV screen.

  2. Get to know your TV's aspect ratio controls. As we discussed before, today's TVs generally have a dedicated button on the remote that lets you quickly cycle through your options. Since the aspect ratio of the programming you're watching can change frequently when you change the channel, for example, or even when a new show begins on the same channel you should get comfortable using these controls to get the picture to your liking.
16 by 9 image on a screen set to 4 by 3

16:9 image on a screen set to 4:3

Below, you'll find some examples of common aspect ratio problems, along with some additional tips for remedying them.

16:9 image on a screen set to 4:3
In this case, the source component is outputting a 16:9 signal, but the TV is displaying it in a 4:3 aspect ratio. You can see that the image has been squished horizontally to fit in this smaller area. We recommend cycling through your aspect ratio options to tell your TV to display a 16:9 image.

Letterbox 16 by9 image on a screen set to 4 by 3

"Letterbox" 16:9 image on a screen set to 4:3

"Letterbox" 16:9 image on a screen set to 4:3
The image in this example has a 16:9 aspect ratio, it's just not filling up the whole screen. Why not? The culprit in this case is often source material formatted for 4:3 TVs, with a 16:9 program on it. The source material includes black bars on the top and bottom to make the 16:9 show fit the 4:3 space. Then, the source component sends that 4:3 signal to your TV and it's either stretched or zoomed to fill the screen, or has pillar box bars on the left and right.

We've come across this problem before in a couple of different situations: (1) Occasionally, channels that normally broadcast shows in 16:9 mistakenly broadcast a 16:9 show in a 4:3 space; (2) Sometimes, DVDs labeled "anamorphic" will have this effect even though they're supposed to fit a 16:9 screen, your DVD player or TV . In both cases, you may be able to correct the problem by adjusting aspect ratio settings on your cable/satellite box or DVD player, but often the easiest (and possibly only) thing you can do is simply zoom the smaller 16:9 image to fill your larger 16:9 screen.

4 by 3 image with pillar box on a screen set to 4 by 3

4:3 image with pillar box on a screen set to 4:3

4:3 image with pillar box on a screen set to 4:3
Here, the source component sent a pillar-boxed 4:3 image in effect, an image made to fit a 16:9 screen. However, the TV is set to display a 4:3 image, so it adds a second set of black bars. We recommend cycling through your aspect ratio options to tell your TV to display a 16:9 image either a pillar-boxed view, or a stretched or zoomed view to get rid of the black bars.

We thank Amanda Moore for this tutorial:
Amanda Moore is a home A/V editor for Crutchfield