Involved with the Resistance effort as a teenager during WWII, Carlsen initially planned to become a doctor after the war's end but became entranced by the cinema and by the writings of Eisenstein and Pudovkin. He subsequently joined Minerva Film in 1948, working as an assistant director to the noted documentarian Theodor Christensen. Over the next dozen years he worked at Minerva, then at Nordisk Studios' educational branch and finally as a freelancer, making about 30 short and medium length documentaries on subjects ranging from motorboats, electricity and milk to civil defense and postmortem procedures. Among his efforts were five films he made about Denmark in 1956 for Disney TV which also played theatrically in his native land. Carlsen was strongly influenced by French ethnographer and cinema verite pioneer Jean Rouch and by the "Free Cinema" documentary movement of Lindsay Anderson and other British filmmakers. Most notable in this regard was his trilogy about three generations of Danes: "Old People" (1961), the first and most important of the three, a remarkably unsentimental and unpatronizing portrait of the elderly; and two follow-ups, "Family Portraits" (1964) and "Young People" (1965). By the time Carlsen was winding up this trilogy he had already formed what would be a lasting working relationship with gifted cinematographer Henning Kristiansen. He had also begun making feature-length fictional films. His debut was an early study of apartheid, the harrowing, documentarian "Dilemma" (1962), shot clandestinely in South Africa and based on Nadine Gordimer's novel "A World of Strangers." Carlsen followed up with several of the grim and intense character studies for which he would become most noted. Both "Epilogue" (1963), which dramatized the conflict between those still dealing with the legacy of the German Occupation and those who grew up afterwards, and "The Cats" (1965), a study of unhappy women toiling in an urban laundry, showed his talent with actors, the grim, mature tone of much of his best work, and his compassion for characters whose harsh lives often lead to unusual behavioral extremes. All these qualities, and Carlsen's considerable talent for literary adaptation, came to the fore with his superb international breakthrough film, "Sult/Hunger" (1966), still considered his masterpiece. A powerful telling of Nobel Prize-winning novelist Knut Hamsun's 1890 study of a gifted but impoverished writer's battles with starvation, madness and his own arrogance, Carlsen elicited a stunning performance from Per Oscarsson in the leading role. He also created a rewarding portrait of urban squalor, and the physical pains, emotional torments and enduring resilience of humanity. None of Carlsen's subsequent films quite recaptured the international acclaim of "Hunger," but he continued doing fine work into the 90s. Evidently eager for a change of pace, he ventured into the hectic erotic fantasia of "People Meet and Sweet Music Fills the Heart" (1967) before making another turn-of-the-century tale of hallucinatory obsession, "We Are All Demons" (1969) and a brief return to documentary with the study of a Maoist commune, "Are You Afraid?" (1970). Carlsen then made three films in collaboration with poet and screenwriter Benny Anderson: "Oh To Be on the Bandwagon" (1972), a typically bittersweet study of the unrealized dreams of a group of regular bar patrons; the black comedy "A Happy Divorce" (1975), with the pent-up passions favored by Carlsen released during a memorable boar hunt; and the odd mystery musical "When Svante Disappeared" (1975). Carlsen received some of the widest acclaim of his career with another of his finest films, "Did Somebody Laugh?" (1978), an adaptation of Eigel Jensen's novel which partially revisited the territory of "Hunger" with its tale of an impoverished loner on the loose in a depressed 1930s Copenhagen. Carlsen's output slowed during the 80s but his work suggested some interesting reflections on his own work as an artist. The minor "Your Money or Your Life" (1982) was, he admitted, quite autobiographical, and he was very sympathetic to the mid-career plight of artist Paul Gaugin (Donald Sutherland), stranded in Paris and unable to afford a return to his beloved Tahiti, in the finely detailed biopic "The Wolf at the Door" (1985). Never quite as overtly metaphysical as Ingmar Bergman, or as splashy as such late 80s new talents as Lars Von Trier, Carlsen found his status and career in a state of partial eclipse. Some found his penchant for literary adaptations a bit too respectful, while others did not discern the readily apparent thematic preoccupations of Bergman or Carl Dreyer. Nonetheless, Carlsen endured as a respected artist of his time, and, after nearly a decade away from features, demonstrated all of his most notable strengths in the splendid "Two Green Feathers/Pan" (1995), a visually lovely and faithful, highly moving adaptation of Hamsun's famous novel of tragically unrequited love, "Pan."