Confused? To put it simply, when films are broadcast in the cinemas, their size and shape is defined by a 16:9 ratio. This is most commonly referred to as “widescreen” format. Usually, however, when we watch television, we watch broadcasts in a 4:3 ratio, what’s known as “fullscreen” format. In the past, when films were shown on television, they were cropped from widescreen to fullscreen format, so that parts of the image would be missing. Now, however, often films are instead scaled down until their width matches the area available, while the height comes up short of the available space. When the film is centered on the screen, this results in a black bar both above and below the actual viewing area. This is becoming less and less of an issue, as more and more televisions are designed for widescreen viewing, but it’s still a neat effect to create in Flash—as if your movie is being viewed on television, instead of on the computer screen.
So how do we do this? First, start off by creating a new document in Flash, at the 4:3 ratio. Mine is 640px x 480px, or basically 4:3 multiplied by 160 on either side. Set the background to black.