After studies at Oxford University and the London School of Economics, Spry began his filmmaking career in 1964 at the National Film Board in Montreal, earning a place on its payroll in 1965.
He built a reputation as a documentarian engaged with the issues of the day, with films on abortion, youth rebellion, and contemporary politics.
His 1970 film Prologue documented the riots at the 1968 Democratic National Convention in Chicago, weaving narrative with archival footage.
His Canadian Film Award-winning documentary Action: The October Crisis of 1970 (1973) used a similar approach to tell the story of the kidnapping of British diplomat James Richard Cross and the murder of Pierre Laporte.
[2] While at the NFB, Spry acted as a producer, director, writer, cinematographer, film editor and actor, appearing in several colleagues' films, including Denys Arcand's Québec, Duplessis et après" (1972), in which he read sections of the 1839 Durham Report.