DVD, HD and Blu-Ray...oh my!

So, you may be asking yourself "Self..what is the difference between my current DVD's and the new HD format disc?"  Go ahead, I'll wait for you to ask.

Finished?  Good, okay well I happen to have found the answer.  In the new world of HD digital media there were two main formats produced: the failed HD-DVD and the champion the Blu-ray disc.  Described in this post is what makes the formats different from regular DVD's and from each other.  We will also discuss why the Blu-ray media format won the HD format war.


The Basics

So, if you've ever seen inside a CD or DVD player you will know that there is a little red laser that reads little pits on the surface of the disc.  In the case of rewritable media, the pits are replaced by burn marks (hence, burning a disc!).  The laser of a CD driver has a wavelength of 780 nanometers (nm) and general use recordable DVD is 640 nm.  The CD laser reads the pits/burns as 1's and 0's, or binary and translates that to the information the computer displays or the stereo projects.  The need for a new HD format was answers by Sony and Toshiba.  Sony created the Blu-ray and Toshiba created the HD-DVD.  The main difference between regular DVD/CD's and HD media is the type laser used.  HD media use a blue laser with a smaller wavelength, 405 nm to be exact.  This means that smaller pits can be used since the laser is smaller and more information can be saved.  However, both HD-DVD's and Blu-rays discs use the same 405 nm blue laser.  If this is true, what should you ask, is the difference between the two?  Furthermore, why did Blu-ray win over HD-DVD?  Good questions, you ask and I'll wait right here.

Good to go?  Okay, lets continue.

The Difference

The distinguishing difference between these two formats is the coating on the disc.  HD-DVD's have the same coating as regular DVD's.  The coating is 0.6 mm thick and allows the HD-DVD to focus at a certain length close to the surface and record so much information.  The coating of a Blu-ray disc is 0.1 mm thick and allows for a longer focus length and therefore store more layers of information.  In the end, Blu-ray won the format war because it could store more information, the production methods were new and the technology to record them was not available to the public (which would limit the ability of criminals to pirate the media) and with the adoption of the format into the Sony PS3, the backing of several prominent movie companies and Disney pushed the market in Sony's favour.  The War was over.