What consumers should know before they buy

A music video of Beyoncé plays at the Blu-Ray booth at the Consumer Electronics Show (CES) in Las Vegas, Tuesday, Jan 8, 2008.

BLU-RAY, which is pronounced 'BLUE RAY', was intentionally spelt without the 'E' so the term could be registered as a trademark. BLU-RAY came on the market a few months after HD DVD with the same intention, to be the successor of traditional DVDs.

BLU-RAY disc format was developed by the BLU-Ray Disc Association (BDA). This association has more than 160 companies with Sony Corporation being one of the leading supporters. BLU-RAY and HD DVD were vying for the takeover of traditional DVDs. However since HD DVD has announced its cessation, this leaves BLU-Ray as the sole winner for next-generation disc format war. Even though HD DVD had a lot of advantages, BLU-RAY also had some of their own. Size capacity is BLU-RAY's greatest advantage, with a minimum of 25 gigabyte (single layer) 50 gigabyte (dual layer) and theory logical discs going as high as 200 to 500 gigabytes.

In August 2008, Blu-ray.com posted: "Pioneer announced that they had developed a 400 gigabyte BLU-RAY disc. Not satisfied that they had exhausted all avenues, they continued to develop and found a way to add four additional layers, bringing the total disc capacity to 500 gigabytes." BLU-RAY also had a faster transfer data rate than that of HD DVD. While HD DVD transfer rate was at a 1X speed which is defined as 36mbps, BLU-RAY movies, however, required a 54mbps transfer rate so the minimum transfer rate we should see is 2X (72 mbps).

doesn't tolerate scratches

Even though there were a lot of advantages for BLU-RAY discs, there were also a few disadvantages as well. Most significant is the fact that a BLU-RAY disc doesn't tolerate scratches too well. Here is why; CD, DVD, HD DVD and BLU-RAY all had a disc thickness of 1.2mm. Their data depths are as follows: traditional DVDs data were burnt 50 per cent (0.6mm) deep into the disc, leaving them with a 50 per cent layer for data protection, which made DVDs friendlier to scratches. HD DVD is build in the same manner with a data depth of 50 per cent (0.6mm), which would offer the same level of scratch resistance of standard DVDs. Now BLU-RAY on the other hand took a different approach, there data is burnt eight per cent (0.1) into the disc which basically left the data very close to the edge. Which means very simple scratches could cause data corruption on a BLU-RAY disc, which in fact did happen with some of the earlier discs that were released. To have an idea of data burning depth concept, music CDs have a data depth of 99 per cent, which allowed it to have scratches on the surface without corrupting the data.

However, BLU-RAY countered this problem by accepting TDK's (a company that is a part of the BLU-RAY Association) protective coating concept. This coating is called Durabis and it's an exclusive coating technology that significantly increases the durability of the BLU-RAY's disc. The Durabis coating has made the disc much more difficult, but not impossible to scratch. Another disadvantage for BLU-RAY is the fact that their format is a bit different from standard DVDs, which meant manufacturers have to retool their factories to build this format. This lead to BLU-RAY discs and players being more expensive compared to HD DVD.

Don't forget to look for part 3 next Wednesday.

Explorers Computer Sales & Service Limited,

34-36 Old Hope Road, Kingston 5

Tel: 849-9381 Email: kamar_mcintyre@yahoo.com

Technical Writer: Kamar McIntyre