This refers to where a copy of a film or video stands in relation to the original material. Film: For example, any camera original material is refered to as the ‘0’ (zero) generation, lets assume that this is an OPN and that a PMP is made from it. From the PMP a PDN is made and that from the PDN a viewing print produced.
In generation terms the OPN is ‘0’, the PMP is ‘1’, the PDN is ‘2’ and the Viewing print is ‘3’. The numbers tell you how far removed you are from the original material. This is only possible if you are familiar with the copying history of any given film.
However copying tends to slightly degrade image quality with each generation and if you are familiar with the film’s copying history you will have some check on copy quality.
Video&Audio: Every recording or re-recording makes another generation of material. Generation loss refers to the degradation caused by the successive recordings. Freshly recorded material is first generation, one re-recording makes the second, and so on. This is of major concern when operating in an analogue edit suite, much less so using an all digital suite, although DVTRs may become subject to tape dropouts (which can be concealed and/or corrected) on a heavily worn tape.
The very best multi-generation results are possible with disk based systems recording the uncompressed CCIR 601 signal. Disks can be re-recorded millions of times without causing dropouts or errors. Generations are effectively limitless.
In recent years the proliferation of video processing equipment such as decoders and DVEs, as well as the use of compression, means there is much more that can now make a significant contribution to generation loss. The quality of such processing equipment should be taken into account.