In 1980, he moved to Toronto, where he founded his own independent production company, Kensington Communications, to produce documentaries for television and non-theatrical markets.

Most recently, Lang's productions include: two one-hour science documentaries, Why We Dance and Nature's Cleanup Crew, for CBC Television's The Nature of Things and Arte; The Shadow of Gold for TVO, Arte France and SVT, co-produced with Films å Çinq and CAPA in Paris, a feature documentary examination of the global gold industry from raw material to market; and between 2015 and 2017, Lang produced two one-hour documentaries, Champions vs Legends and The Equalizer, produced by Kensington Communications in co-production with Berlin Producers for broadcast on CBC’s The Nature of Things, SRC Explora and ZDF/Arte.

In 2015, Lang produced a one-hour documentary for TVOntario and CPAC called The Drop: Why Young People Don't Vote.

Before that he was responsible for several documentary films, including: as producer, co-writer of Raw Opium, which examines the failure of the War on Drugs through the lives of people involved in the international opium trade (TVO, ZDF Arte, SBS); as director/writer/producer of Return to Nepal, in which musician Bruce Cockburn travels to the remote Humla district of Northwestern Nepal (CBC documentary); as co-writer/co-director/co-producer of Almost Home: a Sayisi Dene Journey, an intimate portrait of a Canadian aboriginal community in transition for CBC Nature of Things and APTN; as director/producer of River of Sand, which explores the ancient culture, popular music, and current struggles of the people of Mali, West Africa for Vision TV and TVO; as producer/co-director of Separate Lives, the Gemini-winning documentary which follows the lives of conjoined twins from Pakistan and the pioneering operation that gave them a chance at a new life for Discovery; as director/co-producer of The Biggest Little Ticket, a children’s musical fantasy special for CTV which won several awards and Mariposa: Under a Stormy Sky, a documentary music special for CTV.

Lang was recipient of the Queen Elizabeth II Golden Jubilee Medal in 2002, was named North American Trailblazer of the Year by MIPDOC in 2009 and his work in film and television has garnered many national and international awards (see Awards section below for details).