What are the capacity differences between HD DVD and Blu-ray Disc?
Each next-generation DVD format comes in single-layer and dual-layer formats. For HD DVD, that means capacities of 15GB and 30GB; for Blu-ray Disc, it is 25GB and 50GB. • How should a HD DVD disc be cared for? HD DVD discs should be treated basically the same way a DVD or CD is treated. Keep your HD DVDs and the inside of your player free from dust and debris. Be especially careful not to scratch or put fingerprint marks on the recording surface of the disc, and keep them away from extreme temperatures and humidity. • What are the technical differences between HD DVD and Blu-ray Disc? HD DVD/Blu-ray Disc Format Comparison Chart ParametersBlu-ray DiscHD DVD Capacity per layer (GB)2515 Number of layers1 or 21 or 2 Number of sides11 or 2 Substrate + cover layer (mm)1.1 + 0.10.6 + 0.6 Laser wavelength (nm)405405 Numerical aperture0.850.65 CartridgeNoNo Tilt control neededNoYes Hard coating neededYesNo Complexity to read DVDMore complexNone Data transfer rate36Mbps36Mbps Video CompressionMP
