Nostalgia (1983) IMDb
Andrei Tarkovsky (director).
An unhealthy poet-biographer named Andrei has left Russia to write about an 18th-century composer who was similarly expatriated. Andrei takes his female interpreter to a strange convent but does not enter it, and is later fascinated by an ostensible lunatic who had his family locked away from the world for years.
Excessive elegy. Filmed in Italy with Soviet permission and hardly any lighting. Tarkovsky (re)designed it with the knowledge that he was barred from returning to his country and thereby forbidden to see his family.
References here: The Sacrifice (1986).