Home » DVD Replication: Physical Characteristics & Other Technical Information

DVD Replication: Physical Characteristics & Other Technical Information

The following text is an edited extract from http://en.wikipedia.org/wiki/Dvd

 

DVD types

The five basic types of DVD are referred to by their approximate capacity in gigabytes.

  • Single sided, single layer DVD-5
  • Single sided, dual layer DVD-9
  • Double sided, single layer DVD-10
  • Double sided, dual layer on one side, single on other DVD-14
  • Double sided, dual layer on both sides DVD-18

Disc capacity

  • DVD5 (single layer) contains 4.37 GB (approx 4.7 billion bytes)
  • DVD9 (dual layer) contains 7.95 GB (approx 8.5 billion bytes)
  • DVD10 (single layer on each side of the disc) contains double the DVD5 capacity, since it is effectively two VD5s back to back.

Internal mechanism of a DVD-ROM Drive

DVD uses 650 nm wavelength laser diode light as opposed to 780 nm for CD or 405 nm for Blu-ray Disc. This permits a smaller spot on the media surface (1.32 µm for DVD versus 2.11 µm for CD) compared to CDs.

Writing speeds for DVD were 1×, that is 1350 kB/s (1318 KiB/s), in the first drives and media models. More recent models at 18× or 20× have 18 or 20 times that speed. Note that for CD drives, 1× means 153.6 kB/s (150 KiB/s), 9 times slower.

How Do DVDs Work?

Here is a great guide to the more technical aspects of DVD: http://electronics.howstuffworks.com/dvd.htm