HD-DVD’s are made to accommodate high-definition televisions. While standard DVD’s don’t provide a great picture on screens over 36 inches, HD-DVD’s show up picture-perfect.
They also store a great deal more information—about 48 hours of standard video, as opposed to two or three hours on a standard DVD. You’d think an HD-DVD would need to be much bigger to hold that much more information, but that’s not the case. Here’s how it works.
Video and audio is stored in binary code on a DVD. The binary dots and dashes are engraved into the surface of the disc as a series of different-sized pits. From the other side of the disc, the “pits” protrude as bumps. That’s the side a laser reads and sends to an analog converter, which converts the signal to analog and puts it up on your television screen.
Standard DVD players use red lasers. HD-DVD lasers are blue-violet. Blue light has a shorter wavelength than red, making it more focused and accurate. It can read the much smaller bumps found on an HD-DVD. Since the bumps are a great deal smaller, more information can be stored.
Instead of converting the digital information to an analog signal so the television can read it, an HD-DVD player can send the signal directly to the television in digital format. This makes the image much clearer.
HD-DVD is currently in competition with Blu-Ray, another advanced DVD technology. In many ways, these two technologies are similar. Both use blue lasers, and both store and compress information in a similar way. Blu-Ray has more storage space than HD-DVD. However, Blu-Ray players are more expensive.
Neither technology is ahead at this point—it’s anyone’s game. In the meantime, many consumers are waiting to see which will dominate before upgrading to one or the other.