From 2001: A Space Odyssey to the silent era via Casablanca, Bologna’s ‘found cinema’ festival serves up a magnificent range of classic and rarely seen movies“Technicolor is like God – it cannot be copied!” Nicola Mazzanti of the Royal Belgian Film Archive is introducing a screening of Douglas Sirk’s perfect melodrama All That Heaven Allows (1955) and, in an unexpectedly exuberant speech, he promises the crowd in Bologna’s Cinema Arlecchino “a mystical experience”.