Which is Better...
HD DVD or Blu-Ray Disc?
December 19th, 2007 by Joe Chianese
Last Update January 4th, 2008
Format Wars
If you're old enough, you may remember when VHS and Betamax battled it out for the dominant video storage medium in the 1980s. Obviously,
Betamax didn't make it, and VHS tapes are finally all but gone since DVDs have stolen the video storage market. But today, we're faced with
a new storage medium; two, actually, aiming to accomplish the same goal: become the dominant storage medium for the forseeable future.
Enter HD DVD and Blu-Ray Disc.
HD DVD
An acronym for High Definition Digital Video Disc, HD DVD is the format primarily backed and created by Toshiba (or more technically, a group called the DVD Forum). The first
HD DVD player hit the market on March 31st, 2006, in Japan. The United States had its release on April 16th, 2006. Blu-Ray did not debut
on the consumer market until June of 2006.
In basic terms, HD DVD is just that; high definition DVD. It uses the same technology as DVD except that the laser used to read and write the
discs has a shorter wavelength than that used for regular DVDs. The result is the ability to pack much more data into much smaller areas.
A dual-layer DVD (the same used for movies) can hold 8.54 GB of data, but by using modified DVD production technology (DVDs are written to and read by a red laser,
but HD DVD and Blu-Ray use a blue laser) an HD DVD can hold
15 GB of data on just one layer. A dual-layer HD DVD can fit 30 GB, and recently, triple-layer technology was approved by the DVD Forum,
allowing for 51 GB of storage. This is a subsantially larger storage capacity than plain old DVDs, but it is necessary to fit the
high definition content it was designed for.
A high definition movie can use up the 30 GB of storage space on the typical HD DVD available today. You'll probably see the 51 GB triple-layer
disc become the standard at some point as the need for even more storage becomes a necessity.
The great thing about HD DVD is it uses the same technology as DVD, meaning manufacturers don't need entirely new equipment to
create HD DVDs. The laser used to read and write to the discs needs to be reconfigured for the correct wavelength and some other modifactions are necessary (resulting in the new blue laser with a shorter wavelength). But the significance
is huge: HD DVD is more expensive than DVD technology right now, but it will quickly come down in price and become more and more affordable.
Another cool thing about HD DVD (and newer Blu-Ray players) is its ability to use Picture in Picture. This allows you to watch the movie
and, say, view a directory's commentary in a corner of the screen (just like you can watch two channels on some TVs). Other advanced features
exist for HD DVD that may be specific to the movies themselves. House on Haunted Hill 2, for instance, allows you to interactively
determine the course of the film by route of "choose your own adventure" style multiple-choice questions. Most of the characters
in the film get one of these questionnaires that pops up on your screen during the film asking you how you would like the character to die
or if you'd like the character to escape. Based on your selection, the movie continues the way you want it to. Very cool!
At the time this article was written (December 2007), you can buy an HD DVD player for around $170-$250 and get a few free movies with it.
Keep in mind, you'll need an HD TV to utilize an HD DVD (or Blu-Ray) player. Optimally, you'd want to have an HDMI input. If not, DVI. You can
still yet use component for these two technologies but the quality will be impacted.
Blu-Ray Disc
The rival format, backed and partially developed by Sony Corp., uses a different blue laser (hence the name, Blu-Ray) to write data to the discs. Like HD DVD, Blu-Ray has
an organization behind it known as Blu-Ray Disc Association. Sony is the frontrunner of Blu-Ray, similar to Toshiba promoting HD DVD.
Unlike HD DVD,
Blu-Ray media requires that the data be written closer to the very edges (of the top/bottom) of the disc, meaning it could be very
easily coastered (read: ruined) by small scratches. This is partly why the DVD Forum made its decision to back HD DVD: the Blu-Ray laser was
more expensive, required new machinery for manufacturing, and the discs themselves needed to be enclosed in special plastic cartridges
to protect them from scratches (which also boosted the cost of production). Since its original release, Blu-Ray discs have been updated with a special coating developed by TDK
that prevents data loss from scratches to the surface of the disc. The cartridges are no longer required and they do not continue to contribute to production costs.
So why did Sony go ahead with Blu-Ray? That's a good question. The laser they came up with crams even more data into a smaller region
than HD DVD is capable of, resulting in larger capacity per layer. A single-layer Blu-Ray disc can hold 25 GB, compared to HD DVD's 15 GB.
A double-layer Blu-Ray disc holds, you guessed it, a whopping 50 GB. HD DVD needs the new, less common three-layer disc to provide 50 GB
of storage. Critics are starting to question whether Blu-Ray holds an edge over HD DVD in the capacity department now, which previously
made Blu-Ray the favorite for maximum capacity.
>>Next: Movie Studio Backing and DVD Compatibility (2)
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