Blu-ray Disc Media

Blu-ray disc media comes in pre-recorder, recordable and re-recordable variants. The pre-recorded version is nknown as BD ROM and will primarily be used to distribute high definition versions of movies and TV shows. It will also be the distribution medium for Playstation 3 games.

Recordable Blu-ray media, known as BD R are ideal for archiving large quantities of data or for burning high definition video footage, such as that captured with an HD camcorder, to disc.

Rewritable media, known as BD RE is designed for repetitive usage in the same way as CD-RW and DVD-RW are currently.

All three forms of Blu-ray disc come in both single-layer and double layer formats. Like dual-layer DVD discs, the double-layer discs have two independent layers on one side of the disc and can store twice as much data as single-layer media. This means that double-layer BD media can hold 50GB of data and single-layer discs, 25GB.

The Blu-ray format specification doesn't require Blu-ray players to playback DVD and CD media, however it is likely that most manufacturers will make player which play all three forms of media. This will mean having both blue and red laser components and pickup units. Likewise, CD and DVD recording on a Blu-ray recorder or PC drive is at the discretion of the manufacturer, however, some recorders currently allow DVDs to be recorder and most PC drives will support burning DVDs and CDs.

Unfortunately, the converse is not true. Current DVD players will not be able to play back Blu-ray discs. BD media requires a blue laser to read the very fine pits in the disk, something which DVD players don't have. Also, DVD players don't have the ability to decode high definition video.

Blu-ray discs are made by Fujifilm, Maxell, Panasonic, Sony, and TDK.