DVDs were originally designed for a 135 minute Standard Definition movie and the movie is only slightly compressed in standard definition video (480 x 640 pixels, 30 frames a second in NTSC). At this rate a conventional 4.7 gig DVD holds a full length movie and a few extras.
A conventional DVD cannot hold an entire Hi Def movie. A Hi Def movie would require 5 times the storage space! So the electronics industry started inventing the next generation DVD.
Two Formats: Blu-ray DVD and High-Definition DVD
They both use a new blue laser and the disc looks the same. The blue laser is a shorter wavelength than a red laser which is used in conventional DVDs. This shorter wavelength allows the burning of smaller pits and lands and allows the tracks to be closer together. Blu-ray has more capacity of 23 gigabytes compared to 15 gigs on a HD-DVD disc, but both can double their capacity by recording on two layers.
Developing The Blu-Ray Format
- Panasonic (Matsushita)
- Thomson (RCA and GE)
Developing The HD-DVD Format
The battle was been won by Blu-ray!Â Blu-ray HD-DVD recorders first appeared in Japan in April 2003, and now they are ubiquitous. Those early recorders were designed for home recording only (not for playing pre-recorded HD movies). Now many Blu-ray recorders are downward compatible and play your current DVDs and make them look better. Of course all the DVD players we have now will be obsolete when and if Blu-ray Hi Def DVD players take over. But before you throw your DVD player out, remember what happened with HDTV in the U.S. It was supposed to be available in 1989, yet it was not finalized until 1996 and did not appear until 1998. It hasn’t made your TV set obsolete yet and it won’t for a long time.