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Tips and technical terms for DVDs
2002 was the year it first surpassed the VHS cassette in volume sales. Some six billion units of the pre-recorded version alone were produced last year around the world. What is it? The celebrated Digital Versatile Disc of course, or DVD for short. The storage capacity of even the simplest type is about seven times greater than that of a CD at the same diameter of 12 centimeters.
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| Which DVD is the right one? – There are several things to consider when recording data on the discs. |
But surprisingly, not all DVDs are the same. The technical features and variety make DVDs a science of their own. We've compiled a crash course to help you unravel all the technical terms:
DVD capacities: A DVD comprises two discs, often made of Makrolon®, which have a thickness of 0.6 millimeters and are bonded together. A maximum of four layers in this double-disc structure can hold one information layer each, thus resulting in the different storage capacities: a DVD 5 has one storage layer, corresponding to a capacity of 4.7 gigabytes, and a DVD 9 has two data layers with a total storage space of 8.5 gigabytes. A DVD 10 similarly has two information layers (9.4 gigabytes), but has to be turned over to play the other side, just like the good old vinyl record. Finally, a DVD 18 has four storage layers (17 gigabytes) and also has to be turned over.
DVD formats: The first format is pre-recorded DVDs, such as video and audio DVDs, as well as DVD-ROMs, which are just storage media for computer data. The next format is the large group of recordable discs. And this is where the confusion starts, because of the lack of international standards. Different manufacturers sell drives, recorders and blanks in different formats, which sometimes are incompatible. The DVD-R and DVD+R can only be recorded once, while the DVD-RW and DVD+RW can be overwritten up to 1,000 times, according to manufacturer specifications. The symbols "+" and "-" refer to formats that differ with respect to how data is encoded while the disc is being recorded. Another storage medium for computer data available on the market is the DVD-RAM, which reportedly can be overwritten and deleted 100,000 times. The latest product innovation from EDD is a mini DVD-R. With a diameter of just eight centimeters, it is designed for both camcorders and conventional DVD writers. It has a storage capacity of 1.4 gigabytes, corresponding to roughly 30 minutes of video.
Regional code: The regional code is sometimes the cause of a rude awakening when it comes to movies on DVD that were purchased abroad, because it prevents consumers from watching a movie in a region before it appears in theaters there. The DVD player reads the code and compares it to its own regional code. If it's not a match, the screen will stay blank.
Compatibility: If you have an impressively large collection of pre-recorded CDs, you can also play them on DVD players. However, CD-Rs you recorded yourself can only be played on DVD units with two lasers.
This "infomarathon" may have worn you out. But once you know the formats, you'll be on the right track especially if you take the advice of Walter Dornstedt of MMORE, a leading European supplier of digital storage media: "Don't go for the cheapest products when buying blanks. That will save you data, time, money and frustration."
Treating the flat discs right is another important requirement for ensuring long-term listening and viewing pleasure. Don't stack DVDs without the case. Put them back in the case right after you've finished playing them, so that they don't get dusty. Don't leave discs on a radiator or a sunlit surface in the car. For cleaning, Dornstedt recommends wetting a fleece cloth with water and dabbing the surface of the DVD (don't rub!).
DVD capacities: A DVD comprises two discs, often made of Makrolon®, which have a thickness of 0.6 millimeters and are bonded together. A maximum of four layers in this double-disc structure can hold one information layer each, thus resulting in the different storage capacities: a DVD 5 has one storage layer, corresponding to a capacity of 4.7 gigabytes, and a DVD 9 has two data layers with a total storage space of 8.5 gigabytes. A DVD 10 similarly has two information layers (9.4 gigabytes), but has to be turned over to play the other side, just like the good old vinyl record. Finally, a DVD 18 has four storage layers (17 gigabytes) and also has to be turned over.
DVD formats: The first format is pre-recorded DVDs, such as video and audio DVDs, as well as DVD-ROMs, which are just storage media for computer data. The next format is the large group of recordable discs. And this is where the confusion starts, because of the lack of international standards. Different manufacturers sell drives, recorders and blanks in different formats, which sometimes are incompatible. The DVD-R and DVD+R can only be recorded once, while the DVD-RW and DVD+RW can be overwritten up to 1,000 times, according to manufacturer specifications. The symbols "+" and "-" refer to formats that differ with respect to how data is encoded while the disc is being recorded. Another storage medium for computer data available on the market is the DVD-RAM, which reportedly can be overwritten and deleted 100,000 times. The latest product innovation from EDD is a mini DVD-R. With a diameter of just eight centimeters, it is designed for both camcorders and conventional DVD writers. It has a storage capacity of 1.4 gigabytes, corresponding to roughly 30 minutes of video.
Regional code: The regional code is sometimes the cause of a rude awakening when it comes to movies on DVD that were purchased abroad, because it prevents consumers from watching a movie in a region before it appears in theaters there. The DVD player reads the code and compares it to its own regional code. If it's not a match, the screen will stay blank.
Compatibility: If you have an impressively large collection of pre-recorded CDs, you can also play them on DVD players. However, CD-Rs you recorded yourself can only be played on DVD units with two lasers.
This "infomarathon" may have worn you out. But once you know the formats, you'll be on the right track especially if you take the advice of Walter Dornstedt of MMORE, a leading European supplier of digital storage media: "Don't go for the cheapest products when buying blanks. That will save you data, time, money and frustration."
Treating the flat discs right is another important requirement for ensuring long-term listening and viewing pleasure. Don't stack DVDs without the case. Put them back in the case right after you've finished playing them, so that they don't get dusty. Don't leave discs on a radiator or a sunlit surface in the car. For cleaning, Dornstedt recommends wetting a fleece cloth with water and dabbing the surface of the DVD (don't rub!).
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