Giulia e Giulia (1988)

Giulia, an American woman living in Italy, becomes depressed and traumatized after her husband Paolo is killed in a car accident on their wedding day. Six years later, Giulia inexplicably finds herself sliding in time between two different worlds where in one she is still struggling with her grief over Paolo's death, and in the other world she is married to Paolo who's alive and well with their five year old son, where Giulia is having an affair with a British gentleman named Daniel, in which the frequent supernatural sliding between these two worlds threaten to drive Giulia crazy when she begins having difficulty in telling them apart and learning which world she is currently living in. (First movie filmed with Sony HDVS camera, in High Definition.)