When Steven Spielberg’s “Raiders of the Lost Ark” made its premiere in 1981, one print reviewer suggested that had the Nazis not already historically existed, it would have been necessary for filmmakers to invent them. It’s doubtful that anyone made the same observation when Mr. Spielberg released “Schindler’s List,” a very different movie with the same villains, a little more than a decade later. “Imaginary Witness: Hollywood and the Holocaust,” a new documentary by Daniel Anker that opens December 25 at the IFC Center, deftly traces the “war between narrative on the one hand and history on the other” (in the words of onscreen commentator and author Neil Gabler) fought by American filmmakers depicting the Third Reich’s bestial legacy.

Mr. Anker’s film uses a dream team of film experts and excerpts to fence with what proves to be a long-gestating and still evolving issue. “Hollywood,” offers Columbia University’s Annette Insdorf, “is the means, for better or for worse, by which most people come to terms with the Holocaust.” When Hitler came to power in the 1930s, American film studios, notably Paramount Pictures, had profitably flooded the German film market with American product. During the late ’20s, German audiences accounted for nearly 20% of overseas American studio revenues. Eager to keep the gravy train on track, American producers were initially leery of offending the new German regime. A vintage, pre-war American newsreel narrator in “Imaginary Witness,” for instance, describes a Nazi youth group book burning as “A big night for the young Hitler set.”

Despite the efforts of vehement anti-Nazi industry insiders such as Warner Bros.’s Harry Warner, even once war broke out, the predominantly Jewish-owned studios had difficulty acknowledging and dramatizing the Third Reich’s racist agenda. As always, the darker areas of human psychology were the province of the B-picture and “Imaginary Witness” spotlights such tabloid-pitched dramas as Warner Bros.’s “Confessions of a Nazi Spy” and Columbia’s “None Shall Escape,” which was directed by the Hungarian-born André De Toth soon after his own escape from the advancing German army in Europe. Frank Borzage, one of golden age Tinseltown’s most stirring and perceptive directorial romantics, contributed 1940’s “The Mortal Storm,” a melodrama that shows Margaret Sullivan and Jimmy Stewart eluding Nazi persecution on skis.

Postwar revelations about the intent and extent of the Final Solution also took time to arrive on the big screen. In a particularly illuminating juxtaposition, “Imaginary Witness” details how the 1959 television version of “Judgment at Nuremberg” (with the word “gas” excised from the soundtrack to appease a sponsor) beat Stanley Kramer’s better-known, multiple Oscar-winner to theaters, and how both fictional films were in turn trumped by the real-life courtroom drama of Adolf Eichmann’s war crimes trial, broadcast on American TV in 1961.

By the late ’70s, the American viewing public’s appetite for historically based tragedy made the 1977 slavery drama “Roots” an enormous success and opened the doors for 1978’s “Holocaust.” A multiple-night depiction of Nazi genocide “through,” according to author and educator Michael Berenbaum, “one family that seemed to have been everywhere and done everything,” “Holocaust” was a television event witnessed by one out of every two Americans. It was a photoplay of such oversimplification that Holocaust survivor Elie Wiesel denounced the film as “morally objectionable and indecent.” Eventually Mr. Spielberg himself addresses the influence that increasingly graphic prior depictions of concentration-camp slaughter in documentaries and in television films such as “Holocaust,” and especially “War and Remembrance” (the brainchild of exploitation-tested “Dark Shadows” and “Trilogy of Terror” director Dan Curtis), had on his own Holocaust drama.

In filmmaking, “there is always some degree of manipulation,” Ms. Insdorf says. Each of the artists, survivors, and academics in “Imaginary Witness: Hollywood and the Holocaust” embraces the peculiar mixture of reticence, outrage, and fascination that continues to make any dramatic depiction of Nazi genocide a moral dilemma. The film offers both a cable-ready, generalist survey of Hollywood’s fun-house mirror reflection of history and a subtle diagnosis of America’s not entirely healthy appetite for entertainment posing as fact.

Begins December 25 at the IFC Center (323 Sixth Ave. at West 3rd Street, 212-924-7771).