On Thu, 26 Feb 1998 13:12:44 -0500 Scott Hutchins wrote: > Wouldn't preservation through copying videotapes cause severe > deterioration in image and sound quality. Collectors who pass on bootlegs > at cost always make a big deal about the number of generations down a copy > is, and in my experience I have noted it can be even worse than the > difference between SP and EP. If the video signal is digital, then it is theoretically possible to make an identical copy. All home VHS formats are analogue; that is to say the picture and sound is recorded as a series of waveforms on a magnetic oxide. As you say, when you copy, some of the definition in those waveforms is lost, resulting in replicative fading. With a digital signal, the waveform is represented as numbers and all you have to do is to copy the numbers (exactly like copying a file on a computer disc). However, some professional video formats use a technique called compression: basically, the numbers are crunched to reduce the amount of storage space needed on the tape. Some would argue that the compression and decompression process can have a visible effect on the screen, hence the question mark over format migration and authenticity. As you point out, pirated domestic videos look awful due to this replicative fading. No doubt this is part of the reason why domestic digital videotape has not materialised, as it might result in people being able to make perfect pirate copies. Leo. ---- Online resources for film/TV studies may be found at ScreenSite http://www.tcf.ua.edu/screensite