All DVDs have a resolution of 720 x 480 pixels. Simple math says that if the pixels were square the frame would have an aspect ratio of 1 x 1.5. But the pixels are never displayed as squares. If the image is supposed to be 1.33x1 (as in a pre- 1950s movie, many TVs shows or these girls at Mardi Gras) the DVD player makes the pixels taller than they are wide. If the image is supposed to be 16x9 (as in a widescreen TV show like The Sopranos, Babylon 5, most contemporary movies or this shot of my friends Ray Jay and Caroline) the DVD player makes the pixels wider than they are tall.
In the native DVD matrix the Mardi Gras girls look a little too thick... |
...and Ray Jay and Caroline look a little too skinny. |
On a 1.33x1 Screen the sexy girls are returned to their skinny apperance. |
On a Widescreen 16x9 TV Ray Jay and Caroline no longer look anorexic. |
Of course since most of us don’t have 16x9 TVs yet we need a way to watch these anamorphicly enhanced DVDs. The DVD player throws out every 4th line of resolution and puts black bars at the top and bottom of the frame. Now we have can see it in the original aspect ratio.
If you want to watch the 1.33x1 image on a widescreen TV you have 3 options.
You can see it in the original aspect ratio with black bars on the side (the best option) | stretch the image out the fill the screen, making the girls look too wide | crop off the top and bottom of the image, meaning we won’t see the girl’s legs any more |
Enhanced for 16x9 TVs |
Not Enhanced for 16x9 TVs |
Notice that in the anamorphic one you have more image area and less empty black space.
Enhanced for 16x9 TVs
On a 1.33x1 screen every 4th line is thrown out and black bars are added to the top and bottom of the screen. The image is now made of 720x273 pixels, the same as the non-anamorphic DVD. NOTE: In real life those bars would be black and blend with the ones already in the image. |
Not Enhanced for 16x9 TVs
On a 1.33x1 screen the image is made of 720x273 pixels. |
On a 1.33x1 TV the anamorphic and non-anamorphic versions will look the same. On a Widescreen TV the anamorphic image will fill the screen in the correct aspect ratio.
On a Widescreen TV you have 3 options to watch a nonanamorphic letterboxed DVD.
You can watch it with black bars added to the side and a small image in the center of the scren | crop off the top and bottom of the image, giving you a low resolution image that's only 720x273 pixels | Streatched out to fill the screen, giving you an image where the girls at this Halloween party look short and fat. |
Once you understand the basics it’s not all that hard to understand. Unfortunately many today don’t understand the basics. I’ve walked into electronics stores, bars and people’s houses where DVD players are set up wrong. The most common mistake that people make is having the DVD player outputting an image for a 16x9 TV onto a 1.33x1 screen. In bars and homes it’s an understandable mistake and I’ve shown several of my friends how to set up there DVD players correctly. In an electronic store; lets just say I personally don’t want to buy any video equipment from someone who doesn’t even know how to use a DVD player. So the next time you walk into a bar or a party where a 1.33x1 TV is showing an image that is too tall and thin, or a widescreen is showing one that’s too shot and fat smile and know that you know more than they do about there expensive video system.
Copyright 2003 by:
Brian Fitzgerald