Lars Kraume's "Measures of Men" tells the story of a German ethnologist who travels to what was German South West Africa in the early 1900s to study the country's indigenous peoples and harvest their skulls.
The film was released in German cinemas on March 23 and has also been the subject of special screenings, including in schools and the Bundestag lower house of parliament.
"The colonial era was long repressed by Germany, which lost all its colonies in 1919," Kraume, 50, told AFP.
"This film is a contribution to making Germans aware of their responsibilities," he said.
But only one other film, "Morenga" by German director Egon Guenther, based on the novel of the same name by Uwe Timm, has been made in Germany about the country's role in Namibia.
Germany was responsible for mass killings of indigenous Herero and Nama people that many historians refer to as the first genocide of the 20th century.
Over the past 20 years, Germany has been gradually starting to talk more about the massacre, in which at least 60,000 Herero and 10,000 Nama were killed between 1904 and 1908.
Germany has returned skulls and other human remains to Namibia that it had sent to Berlin during the period for "scientific" experiments.
And in May 2021, the country officially acknowledged that it had committed genocide in Namibia and promised a billion euros in financial support to descendants of the victims.
"Since the centenary of the genocide in 2004, historians and activists have done a lot of work on the subject," said Joel Glasman, a professor of African history at the University of Bayreuth.
Israel Kaunatjike, a Herero rights activist based in Berlin, said "Measures of Men" had "moved me deeply."
"It motivated me to continue to fight for our cause," said the 76-year-old, who was an anti-apartheid resistance fighter when Namibia was still under South African control.
When "Measures of Men" was shown in some Herero villages, "it was very emotional, people thought Lars Kraume was brave to show such a film to the descendants of the victims," Kaunatjike said.
Both Kaunatjike and Kraume believe Germany still has some way to go to reckon with its colonial past.
"We need an official request for forgiveness from the German president in Namibia and the return of all the Herero and Nama skulls and bones still in German collections for burial," said Kraume.
For Kaunatjike, "development aid is no substitute for reparations."
Germany's Namibia Past Portrayed On-Screen
BERLIN - Long overshadowed by World War II and the Holocaust, a colonial-era genocide committed by Germany in Namibia has been brought to the big screen, shining a light on the country's neglected crimes.