Many advances have been made in CD and DVD technology since the invention of the CD, then called the Laserdisc, in 1969. Though Blu-ray technology has been used for years, many people are uncertain about welcoming Blu-ray into their home entertainment experience. What is the difference between HD DVD and Blu-ray?
The basic technology of the HD DVD and Blu-ray are essentially the same, though there are two main differences between HD DVD and Blu-ray. Both the HD DVD and Blu-ray use the same 405nm wavelength blue-violet laser. A Blu-ray disc has a tighter track pitch. The tighter track pitch allows the Blu-ray discs to hold more data than HD DVD discs. The HD DVD discs have a thicker clear plastic overlay to protect the surface of the DVD. The plastic layer of an HD DVD is 0.6 mm thick while the covering on a Blu-ray disc is only 0.1 mm thick.
The Blu-ray discs cannot have a thicker plastic layer, because a thicker layer of plastic would interfere with the lasers ability to read the data on the disc with its tight track pitch. A plastic coating of only 0.01 mm thick is not sufficient to protect the discs. Therefore, the manufacturers of Blu-ray discs must apply a protective coating called Durabis. Applying this coating to the Blu-ray discs is more expensive than having a thicker plastic coating which is why Blu-ray discs cost more than HD DVD discs.
Most of the movie studios and movie rental giants supported Blu-ray over HD DVD format. In early 2008, Toshiba announced that the company would discontinue producing HD DVD players and recorders. Within a month after Toshiba’s announcement, the HD DVD Promotion Group and the major supporters of the HD DVD format ended their promotional efforts and support.
Many consumers are reluctant to purchase Blu-ray discs. The most common reason for a lack of consumer support for Blu-ray is the cost. Blu-ray discs are more expensive than standard DVD’s. Not everyone is willing to replace their standard DVD players for a Blu-ray player. Some people are leery of newer technology for fear that it may suffer the same fate as the HD DVD.
In addition to the cost of a Blu-ray player, people do not get the benefit of the high resolution of Blu-ray unless they are using an HDTV. A common worry is that switching to Blu-ray means that the person can no longer watch their standard DVD’s. However, most Blu-ray players will play standard DVD’s.