Fields of Sacrifice (1964) is considered Brittain's first major film as director. His other notable directorial credits include the 1964 feature documentary
Bethune, 1965 documentaries
Ladies and Gentlemen... Mr. Leonard Cohen and
Memorandum and the
Genie Award-winning 1979 documentary
Paperland: The Bureaucrat Observed. He also directed the first-ever
IMAX film,
Tiger Child for
Expo '70, and
Earthwatch, a 70mm film for
Expo 86. He wrote the 1975 Oscar-nominated short documentary
Whistling Smith. He co-directed the 1976 feature documentary
Volcano: An Inquiry Into the Life and Death of Malcolm Lowry which garnered 6
Canadian Film Awards and an
Academy Award nomination. Brittain also directed the three-part
CBC-coproduced series
The Champions, chronicling the lives and battles of Canadian political titans
René Lévesque and
Pierre Elliott Trudeau. His most ambitious project was
The King Chronicle, a three-part 1987–88 television series about the remarkable career of Prime Minister
William Lyon Mackenzie King. He won the
Gemini Award for best screenplay and direction for the 1985 drama ''
Canada's Sweetheart: The Saga of Hal C. Banks''. As NFB producer, Brittain's credits included
Arthur Lipsett's
A Trip Down Memory Lane. Often a narrator of his own documentaries, Brittain also lent his voice to the animated
mockumentary What on Earth! ==Lifetime achievement awards and posthumous honours==