What are the technical differences between DVD and Blu-ray Disc?
Parameters DVD Blu-ray Disc Capacity per layer (GB) 4.7 25 Number of layers 1 or 2 1 or 2 Number of sides 1 or 2 1 Substrate + cover layer (mm) 0.6 + 0.6 1.1 + 0.1 Laser wavelength (nm) 650 405 Numerical aperture 0.60 0.85 Cartridge No No Hard coating needed No Yes Complexity to read DVD – More complex Data transfer rate 11.08Mbps 36Mbps Video Compression MPEG-2 MPEG-2, MPEG-4 AVC, SMPTE VC-1 *Recording Time (HDTV)Single-Layer – 2 hours 48 min. Dual-Layer – 5 hours 36 min. * All record times based on 19.4Mbps United States ATSC Broadcast Rate and MPEG-2 encoding. • What about my existing DVD collection? There is no official standard that says DVDs will have to be supported by BD devices, but the general consensus is that all BD devices will support DVDs, without requiring any major modifications on the manufacturer’s part. While it is not compulsory for manufacturers, the Blu-ray Disc Association recommends that Blu-ray Disc drives should be capable of reading DVDs, ensuring backward c
