Conversely, Blu-ray, which was developed outside of the DVD Forum, takes a more radical approach to the problem of high definition content delivery. By using a numerical aperture of 0.85, higher than DVD (0.6) or HD DVD, (0.65) which means that the laser's spot can be focused on a smaller point, Blu-ray discs will hold 25GB per layer, for 50GB dual layer discs. Even more impressively, 200GB discs with 8 layers have been demonstrated in the lab.
Another major difference is the protective surface layer. While CDs, DVDs, and HD DVDs all have 0.6mm of protective plastic above and below the actual data layer, there is a mere 0.1mm of plastic under the data layer of a Blu-Ray disc. This thinner layer means less optical losses and greater accuracy, but initially caused worries as small scratches would destroy the disc. Initial plans called for Blu-ray discs to be encased in caddies to keep them from being scratched, but the development of a cheap, effective hard coating technique by TDK, called Durabis, means that Blu-ray discs will be caddyless like current DVDs. TDK also claims that despite the thinner layer, the coating will result in increased durability over existing optical media, saying that it will stand up to being scratched by a screwdriver.
A look at the Blu-ray Disc Association's Board of Directors is like a who's who of the tech industry. Supporters include Apple, Dell, HP, and Hitachi; LG, Mitubishi Electronics, Panasonic, and Pioneer; Phillips, Samsung, Sharp, and Sony; TDK, Thomson, Twentieth Century Fox, Disney, and Warner Brother's Entertainment. In spite of all these heavy-hitters, Blu-ray has yet to actually release a product. Initially slated for release on May 23, 2006, the date has been pushed back to June 2006. The delay is obviously a blow against the standard, but it may have a positive effect in that there may be more titles available on Blu-ray available when the players are released. The Blu-ray Disc Association's website proudly features a long list of pre-announced titles from almost all of the major studios.
So, which standard will win out in this grudge match? Both have advantages and disadvantages. Blu-ray's goals are loftier and it dominates HD DVD on the spec sheets, with higher initial and projected capacities, data rates, and superior durability. On the other hand, HD DVD is available now, and is perfectly satisfactory for the demands of current high definition content. The decision may actually come down to gamers.
Microsoft's XBOX360 is slated for an external HD DVD drive some time this year, and Sony's highly anticipated Playstation 3 is currently specified to ship with a Blu-ray drive in time for the holiday season. Whichever console sells better may be key to the dominance of one standard over the other. The other big unknown is the Adult Entertainment industry, which was a major decider in the VHS/Betamax fight of the 80s.
What can we suggest? Don't throw out your DVDs and trash your player quite yet. It's still very much a case of wait and see, and the loser may very well be caught with a lot of proprietary technology that is as useless as it is expensive.