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DVD  - Frequently Asked Questions

What is DVD?
It is a type of high density compact disc that can hold from 7 to 14 times as much information as a conventional CD. It can hold video, audio, or computer data. At the present time, DVDs are used mostly for playing movies, although computer drives also use DVD-ROM discs.

What do the letters DVD stand for?
Officially, nothing. But many people translate the letters as Digital Versatile Disc or Digital Video Disc.

What are the DVD format types?
The most common ones are:

DVD-5 Stores 4.7 Gbytes Data on 1 side in 1 layer
DVD-9 Stores 85. Gbytes Data on 1 side in 2 layers
DVD-10 Stores 9.4 Gbytes Data on 2 sides in 1 layer
DVD-18 Stores 17.0 Gbytes Data on 2 sides in 2 layers

Why are there different formats?
To accommodate different amounts of data. One side of one disc can hold about two hours’ worth of video and audio, but of course some movies are longer than that. Some of the first long movies on DVD needed to be flipped partway through; new technology allows about four hours of seamless playback on one two-layer side. In some cases, publishers have put two versions of a movie –wide screen and so-called "pan and scan" – on the two sides of a disc, so purchasers can have a choice. Only about 5 percent to 10 percent of movies are too long to fit on one side of a DVD disc.

Is a DVD disc made like a CD?
In many ways, the process is similar, but there are some big differences. The DVD disc is made of two layers, each half the thickness of a CD. So when they’re bonded together they are as thick as a CD (1.2 mm). The pits of a DVD disc are half as big, and much more closely spaced, than those of a CD. That means the laser that "reads" the disc must be smaller and more sharply focused.

Are all DVD discs compatible with all DVD players?
Generally, yes. For legal reasons, some publishers encode DVD discs so that they may play only in certain parts of the world. This is called "regional coding."

Are DVD players compatible with my television now?
Yes. You just hook it up as you would any other accessory.

What about High Definition Television (HDTV)?
At the present time, DVD won’t work with HDTV because its data rates are so much higher.

Do DVD players play my present CDs too?
Yes.

What can DVD do that VHS videotape can’t?
To begin with, the picture and sound quality of DVD are far superior to that of VHS. The discs won’t wear out or degrade over time, as tape will. They can’t be accidentally erased. Plus DVDs can have many extra features such as a choice of languages on the sound track, the ability to play back favorite sections instantly, special-effects playback (such as slow-motion), the choice of parental "locks" on objectionable scenes, and in some cases the ability to select different camera angles, such as in a filmed concert. The audio is better than that of a CD.

How about compared with laserdiscs?
The quality of DVD video has generally been judged better than that of laserdiscs.

Can labels be printed on DVD discs?
It depends on the type of disc. If it is single-sided, a label may be printed on the top side. But because DVDs are more susceptible to heat than CDs are, silk-screening – which uses ultraviolet heat – may not be the best choice. Ink also affects the flatness of DVDs more than CDs. So-called "pit art" was developed to avoid these problems. In it, the pits are recorded only in some parts of a disc side, in a graphic pattern that gives the appearance of a design or a label.

If a DVD disc has data on both sides, neither silk-screening nor pit art may be used on the main surface. The so-called "mirror band" in the center of the disc may be printed on.

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Phone:  800.704.7648
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