[net.movies] How long does movie copyright last?

custead@sask.UUCP (Der cuss) (10/01/85)

Old movies can be purchased very cheaply on videotape ("Silver
Screen" editions.)  Is this because the copyright has expired
on these, or just because the market won't pay as much as
recent releases.  In any case, how long does copyright last
on movies? and can it be renewed?  It would seem that if
the copyright expired, anyone who happened to have a print
of a flic could do what they want with it.  (Does this account
for the popularity of old movies with some TV stations?)