Understanding Widescreen, Letterboxed, and Pan & Scan

Why are There Black Bars on My TV? Understanding Aspect Ratios

by Clint DeBoer

How DVDs Changed the Way We Watch Movies
DVDs provided the same ability to watch widescreen presentations on our 4:3 standard definition televisions, but with one very important change. The DVD spec allowed the picture to be "pre-squished" into what we now call anamorphic (or sometimes dubbed "widescreen") video. Without processing, this condensed video would appear on a 4:3 television as if everyone were tall and skinny. DVD players, however, could take this content and stretch it back out to the correct aspect ratio and provide the black bars on top and bottom. In case you missed the critical difference between the way DVDs and VHS handle this realize that the DVD is using up to its full potential of resolution to store the picture. It does not necessarily need to waste precious video real estate on black bars (we're generalizing for simplicity; there are actually many aspect ratios where a small amount of black bars must be encoded.)

Don't Some DVDs Actually Letterbox Films and Encode Black Bars?
Yes, but those DVDs are generally very old movies sold for $10 or less that are simply a quick transfer from some master in order to get the content to market expeditiously. When the DVD format first came out there were instances of confusion as DVD authoring was still new, however most current or remastered mainstream films are encoded correctly as anamorphic.

High Definition Televisions and Aspect Ratios I Still See Black Bars!!!

Yes, HDTVs did not eliminate the need for black bars. What we hope, is that once people understand the reason for this, it won't bother them nearly as much. HDTV did for television what DVD did for home video and it's now doing so at about the same amazing pace. Widescreen TVs, and high definition television programming is set at a 16:9 (or 1:1.78) aspect ratio. They match. What doesn't match are many films which are shot at a much wider aspect ratio, as well as standard definition and DTV programming which is still at 4:3.

What this means is that even though you now have a brand new high definition television, you will still experience black bars from time to time, or you'll need to scale your video to stretch to fit the TV. In either case, this isn't a bad thing, just part of being involved in a transition period and point of tremendous technological change.

Recommendations for Handling Formats Correctly on Your Television

Before making any recommendations, we'll need to know what kind of television you have and what you're watching. Here are some common scenarios and our suggested guidelines:

  • HDTV with HDTV content: Congratulations, you'll be enjoying the full potential of your television with no black bars or distortion. Be sure your TV is set to its standard (non Zoom, non stretch) mode for the best possible picture.
  • HDTV with standard definition, DTV content, or 4:3/pan-and-scan/full screen DVD: In order to watch content in its proper aspect ratio you'll see black bars on the left and right of the television screen (effectively rendering your new 16:9 television into a 4:3 television.) Another option is to use a stretch or smart stretch mode to fit the content to the full width of the television. Make sure your DVD player is set correctly in 16:9/widescreen mode.
  • HDTV with widescreen/anamorphic DVD: Here you will see black bars on the top and bottom of the picture. This is simply because the original image is wider than the HDTV. To preserve the picture in its entirety, leave the television set to standard mode and be sure your DVD player is set correctly in 16:9/widescreen mode.
  • Standard 4:3 TV with standard definition, DTV content, or 4:3/pan-and-scan/full screen DVD: You won't have any problems playing any of this content on your TV and it will show without any black bars. Make sure your DVD player is set correctly in 4:3/pan-and-scan mode.
  • Standard 4:3 TV with widescreen/anamorphic DVD: Here you will see black bars on the top and bottom of the picture. This is simply because the original image is significantly wider than the TV. To preserve the picture in its entirety, leave the television set to standard mode and be sure your DVD player is set correctly in 16:9/widescreen mode.
  • So where does this leave us? Well, it hopefully explained a bit about aspect ratios and why black bars are going to be a part of your television viewing experience for some time. I also hope it illustrates that these black bars are not necessarily a bad thing as they preserve and display movie content in the manner it was original conceived.
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