Aspect ratio is the ratio of a pictures width divided by its height. Old standard definition TVs were 4×3 or 1.33 aspect ratio. When the HDTV format was developed they decided to change to a wider screen and the 16×9 or 1.78 aspect ratio was born.

This change to a wider screen has had many unintended consequences. Walk into any pizza place in the country and you will probably see a widescreen TV showing a standard def. 1.33 show stretched to fill the screen with all the people stretched unnaturally wide. I find few things as annoying as this. Your TV has a format, zoom or aspect ratio control button so it is actually pretty easy to avoid this problem. Here is how.

First of all watch HD whenever possible. If your cable service provides identical HD and SD channels delete the SD ones. HD programming will fill your screen side to side without distortion on the Wide, Full or 16×9 setting of the aspect ratio control and will look far better as well.

When you do watch SD channels set your aspect ratio to Normal or 4×3. The black bars on the left and right are normal for this format and are far preferable to stretching the image. If the image is widescreen and has black bars on the top and bottom too you can try one of the zoom settings on the aspect ratio button. One of these should let you fill the screen side to side without distorting or cropping the image. Some TVs have an auto setting for the aspect ratio control when using the internal tuner. This should display HD channels full screen and SD channels 4×3. Sometimes HD channels show standard definition programs. In this case set your TV to wide. The black bars on the left and right are normal if the show was shot in standard definition.

Keep in mind that not all TV stations broadcast everything at the correct aspect ratio. It is common for Standard definition channels to show programming squeezed so you have to set your TV to Wide, Full or 16×9 to view them properly. This varies from channel to channel with some showing squeezed content and some showing unsqueezed content. It can even vary from one show to the next on the same channel. Don’t ask me why they do this. The bottom line is you have to adjust your aspect ratio control often with SD channels.

Before discussing showing movies on DVD or Blu-ray or UHD-Blu ray it is important that your player is set for the aspect ratio of your TV, 4×3 or 16×9. This is a menu setting you should find in the video setup menu.

Movies have several aspect ratios. Older pre 1950s movies were 4×3 or 1.33. In the 1950s cinemascope was invented. This gives a very wide 2.35 aspect ratio and will have black bars on the top and bottom when properly shown on any TV. 1.85 was developed as a compromise between 1.33 and 2.35. 1.85 movies are often transferred to video at the 1.78 aspect ratio. This is very close to 1.85 and fills the screen on widescreen TVs. There are also a few other aspect ratios you may occasionally see. 1.66 was used for some European films, 2.20 was used for most films shot in 65mm for 70mm projection. The movies aspect ratio should be labeled on the back of the DVD or Blu-Ray box.

Movies should be presented in their original aspect ratio. When buying or renting DVDs look for the widescreen version of any widescreen film. Avoid the full screen version. This has been reformatted for old 4×3 TVs and you will be missing some of the image. You will also have to show full screen DVDs at the 4×3 settings.

On the back of the DVD box it usually gives the aspect ratio and says “anamorphic widescreen” or “enhanced for widescreen TVs”. These DVDs should be played back with your aspect ratio set to Wide, Full or 16×9 and will give improved picture quality over non anamorphic DVDs. Non anamorphic DVDs should be played back at the normal or 4×3 setting. If the movie is widescreen 1.78, 1.85 or 2.35 you can use one of the zoom settings to fill the screen side to side. If the DVD is 2.35 black bars on the top and bottom are normal.

Blu-Ray is a HD format and should always be played back with your TV set to Wide, Full or 16×9. The same applies to UHD Blu-ray

The bottom line is you should be able to watch any movie or TV program on your new HDTV at the original aspect ratio without distorting the image. Don’t be afraid to change the aspect ratio if people on the screen look too wide, too thin or if part of the image looks cropped. The aspect ratio or format button is your best friend in these days of both standard and HD sources and will enable you to watch anything without image distortion.