HDTV World > Understanding HDTV > CNET's quick guide to aspect ratio

4:3 (standard) TVs

Because they still represent the overwhelming majority of TVs in the marketplace, most television programming is already properly formatted for standard 4:3 TVs. But many movies--on both DVD and cable TV--as well as a small but steadily increasing number of TV shows (for example, Saturday Night Live, ER, Battlestar Galactica and Late Night with Conan O'Brien) are broadcast in wide-screen format. Seen on a 4:3 TV this letterboxing format--named because it duplicates the effect of staring through a mail slot--leaves black bars at the top and bottom of the screen.

Reminder: Before we take a look at the two most common aspect-ratio problems that afflict 4:3 TVs, it's important to ensure that your video sources (DVD player/recorders, game consoles, satellite and cable boxes, DVRs, video iPods, and so forth) are set to the aspect ratio that matches your TV. Devices connected to standard TVs should be set to 4:3. The one exception is for TVs that offer a feature called vertical compression or anamorphic squeeze. Video sources attached to these models should be (counterintuitively) set to 16:9, because they're designed to display the full vertical resolution of a wide-screen image within the letterboxed area.

Undesired letterboxing (wide-screen video on a standard screen)

"How do I get rid of those black bars?" 
Problem: Black letterbox bars appear at the top and bottom of the screen when watching wide-screen content, such as most DVDs and some network TV shows.
Solution: Use the zoom control on the TV or DVD player to get closer to the image.
Upside: The image will fill the screen, or you'll see smaller black bars.
Downside: You'll miss any action on the extreme left and right of the image, which will be cut off. Furthermore, the picture will appear softer because it's being electronically blown up--just like the muddy images one gets when using the digital zoom function on a digital camera.

BEFORE: Letterbox bars are visible at the top and bottom--but you can see how the director intended the shot to look.		AFTER: The image fills the screen, but it's not as sharp, and it cuts off the left and right sides. Who knows what's in The Dude's left hand?

TV and video-source aspect ratio don't match

"Why does everyone on screen look like they're in an El Greco painting?" 
Problem: When playing wide-screen DVDs that are anamorphic (enhanced for 16:9 TVs), everything looks stretched vertically--actors appear taller and thinner than they otherwise would.
Solution: In the setup menu of your DVD player or set-top box, make sure the TV Type (or TV Shape or Aspect Ratio) option is set to 4:3 letterbox or 4:3 pan-and-scan, not 16:9.
Upside: The image will appear in its correct proportions.
Downside: You'll see black bars above and below the image. However, this is the aspect that the director intended. You may also notice anamorphic downconversion artifacts.
Note: Many newer, more expensive 4:3 TVs--especially HDTVs--have a feature called vertical compression, or anamorphic squeeze. For these TVs, the DVD player's setting should be switched (counterintuitively, but correctly) to 16:9. As a result, you'll see a sharper picture with fewer artifacts.

BEFORE: Incorrectly setting the DVD player's output for 16:9 stretches everything to look artificially tall and thin. Note that The Dude's spherical bowling ball is now oval-shaped.		AFTER: Correctly setting the DVD player to match the 4:3 screen displays the image in its correct proportions. The bowling ball correctly shows its circular form.

Standard TVs are pretty straightforward, but aspect-ratio issues can get a bit confusing once you upgrade to a set with a 16:9 screen (most HDTVs, for instance). Let's take a look at how to fix common aspect-ratio problems in the wide-screen world.