Recordable Blu-ray Discs
With the growing demand for high-definition video Blu-ray disc provides an excellent choice for the consumer. Even better is the fact that a recordable Blu-ray format exists that allows for recording your favorite shows in high-definition. Both write-once and rewritable Blu-ray disc media exists in 25GB and dual layer 50GB capacity. Almost 5 times the storage of standard recordable DVDs. Blu-ray recordable represents a huge jump in capacity that not only allows for less compression of the video signal but gives even more room for features that were just a dream in DVD format.
So what makes recordable Blu-ray so much better then DVD?
Blu-ray technology uses a violet-blue laser which operates at a higher frequency then the red laser that DVD relies on. This allows for the information (or pits) to be placed closer together on the same sized disc as DVD. This change of lasers requires additional lasers for backwards compatibility with DVD and CD. Unlike the past format releases (DVD specifically) consumers do not have to face the decision of upgrading to a new format and casting aside their current library. Blu-ray readers and recorders have been designed to provide full support for the older formats.
One of the little known facts of the new BD-R format is it’s construction vs. DVD recordable. Blu-ray recordable discs use a single polycarbonate disc which provides better sealing against oxidation then recordable DVD. Recordable DVD’s use two layers: a sandwich with the dye and reflective layer in the middle. The only thing keeping the DVD recordable disc from separating is glue. As production of DVD recordable has been perfected the separation of the two parts is less likely but still a concern. Not only from the outside of the disc but the hub in the center where it is in contact with a locking mechanism when stored in a DVD case. As this glue fails it allows oxygen to enter the disc at a faster rate then through the plastic itself. Oddly enough recordable CD-R have a far longer archival life then recordable DVD. This is because CD-R (like Blu-ray recordable) has a single layer of polycarbonate with various sealing layers on top that provide greater reduction of oxidation then the DVD sandwich.
So besides the increase in storage capacity Blu-ray also offers greater longevity then recordable DVD media. How much longer is being tested right now by most of the blank blu-ray disc media manufacturers.